@article{HelsperFissan1979,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Numerical Simulation Studies and Data Reduction for Size Classifying Measurement Techniques / Fißan, H. J.; Helsper, C.},
  series = {Aerosols in science, medicine and technology : conference / Gesellschaft f{\"u}r Aerosolforschung 7. 1979.},
  journal   = {Aerosols in science, medicine and technology : conference / Gesellschaft f{\"u}r Aerosolforschung 7. 1979.},
  pages     = {199 -- 205},
  year      = {1979},
  language  = {en}
}
@article{HelsperFissan1980,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Numerical Simulation Studies and Data Reduction for Size Classifying Measurement Techniques / Fißan, H. J.; Helsper, C.},
  series = {Advances in Particle Sampling and Measurement: Proceedings, Daytona Beach, EPA 600/9 80 004, 1980},
  journal   = {Advances in Particle Sampling and Measurement: Proceedings, Daytona Beach, EPA 600/9 80 004, 1980},
  publisher = {National Technical Information Service},
  address   = {Springfield, Va.},
  pages     = {VII, 409 S.},
  year      = {1980},
  language  = {en}
}
@article{HelsperFissanMugglietal.1980,
  author    = {Helsper, Christoph and Fißan, H. J. and Muggli, J. and Scheidweiler, A.},
  title     = {Particle Number Distributions of Aerosols from Test Fires},
  series = {Journal of Aerosol Science. 11 (1980), H. 5-6},
  journal   = {Journal of Aerosol Science. 11 (1980), H. 5-6},
  isbn      = {0021-8502},
  pages     = {439 -- 446},
  year      = {1980},
  language  = {en}
}
@article{HelsperFissan1981,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Response Characteristic of a Polytec HC-15 Optical Particle Counter},
  series = {Aerosols in science, medicine and technology : Physical and chemical properties of aerosols : Association for Aerosol Research: annual conference. 1980 : Gesellschaft f{\"u}r Aerosolforschung: annual conference. 1980 : Aerosols in science, medicine and technology : Physical and chemical properties of aerosols : Associa-tion for Aerosol Research: annual conference. 1980 : Gesellschaft f{\"u}r Aerosolforschung: annual conference. 1980 : Schmallenberg, 22.10.80 - 24.10.80},
  journal   = {Aerosols in science, medicine and technology : Physical and chemical properties of aerosols : Association for Aerosol Research: annual conference. 1980 : Gesellschaft f{\"u}r Aerosolforschung: annual conference. 1980 : Aerosols in science, medicine and technology : Physical and chemical properties of aerosols : Associa-tion for Aerosol Research: annual conference. 1980 : Gesellschaft f{\"u}r Aerosolforschung: annual conference. 1980 : Schmallenberg, 22.10.80 - 24.10.80},
  publisher = {Pergamon Pr.},
  address   = {Oxford},
  pages     = {287 -- 292},
  year      = {1981},
  language  = {en}
}
@book{Helsper1981,
  author    = {Helsper, Christoph},
  title     = {Bestimmung, Simulation und Korrektur des nichtidealen {\"U}bertragungsverhaltens klassifizierender Aerosolmeßverfahren},
  publisher = {Univ.-Gesamthochsch},
  address   = {Duisburg},
  pages     = {65 S.},
  year      = {1981},
  language  = {de}
}
@article{HelsperFissanKapadietal.1982,
  author    = {Helsper, Christoph and Fißan, H. J. and Kapadi, A. and Liu, B. Y. H.},
  title     = {Data Inversion by Simplex Minimization for the Electrical Aerosol Analyzer},
  series = {Aerosol Science and Technology. 1 (1982), H. 1982},
  journal   = {Aerosol Science and Technology. 1 (1982), H. 1982},
  isbn      = {0278-6826},
  pages     = {136 -- 146},
  year      = {1982},
  language  = {en}
}
@article{SpaeteFaberSchwarzeretal.2004,
  author    = {Sp{\"a}te, Frank and Faber, Christian and Schwarzer, Klemens and Hartz, Thomas},
  title     = {Comparison of solar hot water systems in solar settlements - decentralized or centralized systems?},
  series = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 1},
  journal   = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 1},
  publisher = {PSE},
  address   = {Freiburg [Breisgau]},
  isbn      = {3-9809656-1-9},
  pages     = {1-666-1-671},
  year      = {2004},
  language  = {en}
}
@article{KhedimSchwarzerFaberetal.2004,
  author    = {Khedim, Ahmed and Schwarzer, Klemens and Faber, Christian and M{\"u}ller, Christoph},
  title     = {Production d{\´e}centralis{\´e}e de l'eau potable {\`a} l'{\´e}nergie solaire},
  series = {Desalination. 168 (2004), H. 1-3},
  journal   = {Desalination. 168 (2004), H. 1-3},
  isbn      = {0011-9164},
  pages     = {13 -- 20},
  year      = {2004},
  language  = {en}
}
@article{FaberFritzscheSchwarzer2002,
  author    = {Faber, Christian and Fritzsche, Ulrich and Schwarzer, Klemens},
  title     = {Vergleich der Ergebnisse des quasidynamischen und station{\"a}ren Kollektortests nach En 12975-2 / Fritzsche, Ulrich ; Faber, Christian ; Schwarzer, Klemens},
  series = {Zw{\"o}lftes Symposium Thermische Solarenergie : 24. bis 26. April 2002 / [wiss. Gesamtleitung: Volker Wittwer. Veranst.: OTTI-Energie-Kolleg. Mitveranst.: Arbeitsgemeinschaft Kommunaler Versorgungsunternehmen zur Sparsamen Ernergie- und Wasserverwendung (ASEW), K{\"o}ln ...]},
  journal   = {Zw{\"o}lftes Symposium Thermische Solarenergie : 24. bis 26. April 2002 / [wiss. Gesamtleitung: Volker Wittwer. Veranst.: OTTI-Energie-Kolleg. Mitveranst.: Arbeitsgemeinschaft Kommunaler Versorgungsunternehmen zur Sparsamen Ernergie- und Wasserverwendung (ASEW), K{\"o}ln ...]},
  publisher = {OTTI-Energie-Kolleg},
  address   = {Regensburg},
  isbn      = {3-934681-20-4},
  pages     = {135 -- 139},
  year      = {2002},
  language  = {de}
}
@book{HafnerSchwarzerPlettnerMarlianietal.2000,
  author    = {Hafner, B. and Schwarzer, Klemens and Plettner-Marliani, J. and Wemh{\"o}ner, C. and Faber, Christian and Wenzel, T.},
  title     = {Entwicklung einer Heizungs-/Solarthermie "Toolbox" f{\"u}r die Simulationsumgebung MATLAB (EXP trademark) /SIMULINK (EXP trademark) : Abschlussbericht},
  publisher = {Fachhochschule Aachen},
  address   = {J{\"u}lich},
  pages     = {56 S.},
  year      = {2000},
  language  = {de}
}
@article{VelrajSeenirajHafneretal.1997,
  author    = {Velraj, R. and Seeniraj, R. V. and Hafner, B. and Faber, Christian and Schwarzer, Klemens},
  title     = {Experimental analysis and numerical modelling of inward solidification on a finned vertical tube for a latent heat storage unit},
  series = {Solar energy. 60 (1997), H. 5},
  journal   = {Solar energy. 60 (1997), H. 5},
  isbn      = {0038-092X},
  pages     = {281 -- 290},
  year      = {1997},
  language  = {en}
}
@book{PeterStrackeWeinzierletal.1995,
  author    = {Peter, M. and Stracke, Thomas and Weinzierl, C. and Faber, Christian and Schwarzer, Klemens},
  title     = {Verbundvorhaben zur Ermittlung der Leistungsf{\"a}higkeit von Sonnenheizsystemen zur Wassererw{\"a}rmung : Phase 2 (VELS II) ; Abschlussbericht},
  publisher = {Solar-Institut J{\"u}lich, Fachhochschule Aachen},
  address   = {J{\"u}lich},
  pages     = {87 S.},
  year      = {1995},
  language  = {de}
}
@article{SchwarzerFaberStracke1994,
  author    = {Schwarzer, Klemens and Faber, C. and Stracke, T.},
  title     = {Teststelle fuer Warmwasser-Kollektoren und -Systeme},
  series = {Energiewirtschaftliche Tagesfragen. 44 (1994), H. 9},
  journal   = {Energiewirtschaftliche Tagesfragen. 44 (1994), H. 9},
  isbn      = {0720-6240},
  pages     = {41 -- 43},
  year      = {1994},
  language  = {de}
}
@article{BuckSchwarzerMelissetal.1994,
  author    = {Buck, H. and Schwarzer, Klemens and Meliß, Michael and Faber, Christian},
  title     = {Aus- und Weiterbildung am Solar-Institut J{\"u}lich},
  series = {Energiewirtschaftliche Tagesfragen. 44 (1994), H. 9},
  journal   = {Energiewirtschaftliche Tagesfragen. 44 (1994), H. 9},
  isbn      = {0720-6240},
  pages     = {65 -- 68},
  year      = {1994},
  language  = {de}
}
@article{BuckFaberMelissetal.1995,
  author    = {Buck, H. and Faber, Christian and Meliß, Michael and Schwarzer, Klemens},
  title     = {Aus- und Weiterbildung am Solar-Institut J{\"u}lich},
  series = {Energie f{\"u}r die Zukunft : 28. Juni bis 1. Juli 1994 ; [Tagungsbericht 2] / 9. Internationales Sonnenforum '94. [Hrsg. Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS. Red. A. Hohmann ; H. H. Hohmann]. - (Internationales Sonnenforum ; 9,2)},
  journal   = {Energie f{\"u}r die Zukunft : 28. Juni bis 1. Juli 1994 ; [Tagungsbericht 2] / 9. Internationales Sonnenforum '94. [Hrsg. Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS. Red. A. Hohmann ; H. H. Hohmann]. - (Internationales Sonnenforum ; 9,2)},
  publisher = {DGS-Sonnenenergie},
  address   = {M{\"u}nchen},
  pages     = {1779 -- 1785},
  year      = {1995},
  language  = {de}
}
@article{FritzscheFaberSchwarzer2002,
  author    = {Fritzsche, Ulrich and Faber, Christian and Schwarzer, Klemens},
  title     = {Vergleich der Ergebnisse des quasidynamischen und station{\"a}ren Kollektortests nach En 12975-2},
  series = {Zw{\"o}lftes Symposium Thermische Solarenergie : 24. bis 26. April 2002 / [wiss. Gesamtleitung: Volker Wittwer. Veranst.: OTTI-Energie-Kolleg. Mitveranst.: Arbeitsgemeinschaft Kommunaler Versorgungsunternehmen zur Sparsamen Ernergie- und Wasserverwendung (ASEW), K{\"o}ln ...]},
  journal   = {Zw{\"o}lftes Symposium Thermische Solarenergie : 24. bis 26. April 2002 / [wiss. Gesamtleitung: Volker Wittwer. Veranst.: OTTI-Energie-Kolleg. Mitveranst.: Arbeitsgemeinschaft Kommunaler Versorgungsunternehmen zur Sparsamen Ernergie- und Wasserverwendung (ASEW), K{\"o}ln ...]},
  publisher = {OTTI-Energie-Kolleg},
  address   = {Regensburg},
  isbn      = {3-934681-20-4},
  pages     = {135 -- 139},
  year      = {2002},
  language  = {de}
}
@article{SchwarzerWernerHartz2004,
  author    = {Schwarzer, Klemens and Werner, M. and Hartz, T.},
  title     = {Lacasa - an instrument for the energy analysis and optimisation of buildings including technical equipment},
  series = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 2},
  journal   = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 2},
  publisher = {PSE},
  address   = {Freiburg [Breisgau]},
  isbn      = {3-9809656-2-7},
  pages     = {2-489-2-494},
  year      = {2004},
  language  = {en}
}
@article{HelsperFissanFranzen1976,
  author    = {Helsper, Christoph and Fißan, H. J. and Franzen, H.},
  title     = {Bestimmung der Gr{\"o}ßenverteilung von Aerosolen aus Verbrennungsvorg{\"a}ngen mit einem elektrostatischen Aerosolanalysator},
  series = {Aerosole in Naturwissenschaft, Medizin und Technik : Bericht der Tagung der Gesellschaft f{\"u}r Aerosolforschung e.V. 4, 1976},
  journal   = {Aerosole in Naturwissenschaft, Medizin und Technik : Bericht der Tagung der Gesellschaft f{\"u}r Aerosolforschung e.V. 4, 1976},
  pages     = {118 -- 126},
  year      = {1976},
  language  = {de}
}
@article{HelsperFissan1982,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Techniken zur Kalibrierung von Staubmeßger{\"a}ten / Fißan, H. J.; Helsper, C.},
  series = {Schwebstoffe und St{\"a}ube : analyt. u. techn. Aspekte ; Kolloquium N{\"u}rnberg 1981},
  journal   = {Schwebstoffe und St{\"a}ube : analyt. u. techn. Aspekte ; Kolloquium N{\"u}rnberg 1981},
  publisher = {VDI-Verl.},
  address   = {D{\"u}sseldorf},
  isbn      = {3-18-090429-1},
  pages     = {59 -- 64},
  year      = {1982},
  language  = {de}
}
@article{HelsperFissan1982,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Zur Reaktion von Rauchdetektoren auf Brandkenngr{\"o}ßen / Fißan, H. J.; Helsper, C.},
  series = {Tagungsbericht zum Internationalen Vortragsseminar {\"u}ber Probleme der automatischen Brandent-deckung / Institut f{\"u}r Elektrische Nachrichtentechnik. Technische Hochschule Aachen ; Fachgebiet Nachrichtentechnik. Universit{\"a}t Duisburg, Gesamthochschule . 8. Internationales Vortragsseminar "AUBE 82"},
  journal   = {Tagungsbericht zum Internationalen Vortragsseminar {\"u}ber Probleme der automatischen Brandent-deckung / Institut f{\"u}r Elektrische Nachrichtentechnik. Technische Hochschule Aachen ; Fachgebiet Nachrichtentechnik. Universit{\"a}t Duisburg, Gesamthochschule . 8. Internationales Vortragsseminar "AUBE 82"},
  address   = {Duisburg},
  pages     = {20 -- 37},
  year      = {1982},
  language  = {de}
}
@article{HelsperFissanMugglietal.1983,
  author    = {Helsper, Christoph and Fißan, H. J. and Muggli, J. and Scheidweiler, A.},
  title     = {Verification of Ionization Chamber Theory},
  series = {Fire Technology. 19 (1983), H. 1},
  journal   = {Fire Technology. 19 (1983), H. 1},
  isbn      = {1572-8099},
  pages     = {14 -- 21},
  year      = {1983},
  language  = {en}
}
@article{HelsperFissan1983,
  author    = {Helsper, Christoph and Fißan, H. J.},
  title     = {Calibration of the Polytec HC-15 and HC-70 Optical Particle Counters / Fißan, H. J. ; Helsper, C.},
  series = {Aerosols in the mining and industrial work environments, Vol. 3. Instrumentation, Marple, Virgil A. ; Liu, Benjamin Y.},
  journal   = {Aerosols in the mining and industrial work environments, Vol. 3. Instrumentation, Marple, Virgil A. ; Liu, Benjamin Y.},
  publisher = {Ann Arbor Science},
  address   = {Ann Arbor, Mich.},
  pages     = {825 -- 829},
  year      = {1983},
  language  = {en}
}
@article{HelsperFissanKasper1984,
  author    = {Helsper, Christoph and Fißan, H. J. and Kasper, W.},
  title     = {Kalibrierung der Partikelgr{\"o}ßenbestimmung von optischen Partikelz{\"a}hlern / Fißan, H. J.; Helsper, C. ; Kasper, W.},
  series = {3. Europ{\"a}isches Symposion Partikelmeßtechnik : [PARTEC, eine Veranstaltung der Reihe Partikel-Technologie N{\"u}rnberg ; N{\"u}rnberg, 9. - 11. Mai 1984 ; preprints] = 3. European Symposium on Particle Characterization / Veranst.: GVC, Gesellschaft Verfahrenstechnik und Chemieingenieurwesen im Verein Deutscher Ingenieure (VDI). Red. Bearb.: Kurt Leschonski},
  journal   = {3. Europ{\"a}isches Symposion Partikelmeßtechnik : [PARTEC, eine Veranstaltung der Reihe Partikel-Technologie N{\"u}rnberg ; N{\"u}rnberg, 9. - 11. Mai 1984 ; preprints] = 3. European Symposium on Particle Characterization / Veranst.: GVC, Gesellschaft Verfahrenstechnik und Chemieingenieurwesen im Verein Deutscher Ingenieure (VDI). Red. Bearb.: Kurt Leschonski},
  publisher = {NMA N{\"u}rnberger Messe- und Ausstellungsges.},
  address   = {N{\"u}rnberg},
  pages     = {263 -- 274},
  year      = {1984},
  language  = {de}
}
@article{HelsperNiessnerRoenicke1984,
  author    = {Helsper, Christoph and Nießner, R. and R{\"o}nicke, G.},
  title     = {Application of a Multistep Condensation Nuclei Counter as a Detector for Particle Surface Composition / Nießner, R.; Helsper, C.; R{\"o}nicke, G.},
  series = {Aerosols : science, technology, and industr. applications of airborne particles ; proceedings of the 1. Internat. Aerosol Conference held Sept. 17-21, 1984, Minneapolis, Minn., U.S.A / ed.: Benjamin Y. H. Liu},
  journal   = {Aerosols : science, technology, and industr. applications of airborne particles ; proceedings of the 1. Internat. Aerosol Conference held Sept. 17-21, 1984, Minneapolis, Minn., U.S.A / ed.: Benjamin Y. H. Liu},
  publisher = {Elsevier},
  address   = {New York [u.a.]},
  isbn      = {0444009477},
  pages     = {63 -- 66},
  year      = {1984},
  language  = {en}
}
@article{HelsperFissanThielen1983,
  author    = {Helsper, Christoph and Fißan, H. J. and Thielen, H. J.},
  title     = {Determination of Particle Size Distributions by Means of an Electrostatic Classifier / Fißan, H. J.; Helsper, C. ; Thielen, H. J.},
  series = {Journal of Aerosol Science. 14 (1983), H. 3},
  journal   = {Journal of Aerosol Science. 14 (1983), H. 3},
  isbn      = {0021-8502},
  pages     = {354 -- 357},
  year      = {1983},
  language  = {en}
}
@article{HelsperFissanKasper1984,
  author    = {Helsper, Christoph and Fißan, H. J. and Kasper, W.},
  title     = {Calibration of Optical Particle Counters with Respect to Particle Size / Fißan, H. J. ; Helsper, C.; Kasper, W.},
  series = {Particle and Particle Systems Characterization. 1 (1984), H. 1984},
  journal   = {Particle and Particle Systems Characterization. 1 (1984), H. 1984},
  isbn      = {1521-4117},
  pages     = {108 -- 111},
  year      = {1984},
  language  = {en}
}
@article{HelsperNiessner1985,
  author    = {Helsper, Christoph and Nießner, R.},
  title     = {Application of a Multistep Condensation Nuclei Counter as a Detector for Particle Surface Composition / Nießner, R. ; Helsper, C.},
  series = {Journal of Aerosol Science. 16 (1985), H. 3},
  journal   = {Journal of Aerosol Science. 16 (1985), H. 3},
  isbn      = {0021-8502},
  pages     = {201 -- 209},
  year      = {1985},
  language  = {en}
}
@article{HelsperBartzFissanetal.1985,
  author    = {Helsper, Christoph and Bartz, H. and Fißan, H. J. and Kousaka, Y. (u.a.)},
  title     = {Response Characteristics for Four Condensation Nucleus Counters to Particles in the 3 to 50 nm Diameter Range / Bartz, H. ; Fißan, H. J. ; Helsper, C.; Kousaka, Y. ; Okuyama, K. ; Keady, R. Fruin, S. ; McMurry, P. H.; Pui, D. Y. H. ; Stolzenburg, M. R.},
  series = {Journal of Aerosol Science. 16 (1985), H. 5},
  journal   = {Journal of Aerosol Science. 16 (1985), H. 5},
  isbn      = {0021-8502},
  pages     = {443 -- 456},
  year      = {1985},
  language  = {en}
}
@article{HelsperNiessner1985,
  author    = {Helsper, Christoph and Nießner, R.},
  title     = {On the Influence of the Vapour Substance on the Behaviour of an Expansion Type Condensation Nucleus Counter},
  series = {Journal of Aerosol Science. 16 (1985), H. 5},
  journal   = {Journal of Aerosol Science. 16 (1985), H. 5},
  isbn      = {0021-8502},
  pages     = {457 -- 461},
  year      = {1985},
  language  = {en}
}
@article{HelsperWiedensohlerLuetkemeieretal.1986,
  author    = {Helsper, Christoph and Wiedensohler, A. and L{\"u}tkemeier, E. and Feldpausch, M.},
  title     = {Investigation on the Bipolar Charge Distribution at Various Gas Conditions / Wiedensohler, A.; L{\"u}tkemeier, E.; Feldpausch, M. ; Helsper, C.},
  series = {Journal of Aerosol Science. 17 (1986), H. 3},
  journal   = {Journal of Aerosol Science. 17 (1986), H. 3},
  isbn      = {0021-8502},
  pages     = {413 -- 416},
  year      = {1986},
  language  = {en}
}
@article{HelsperDreilingHalleretal.1986,
  author    = {Helsper, Christoph and Dreiling, V. and Haller, P. and Kaminski, U.},
  title     = {Intercomparison of Eleven Condensation Nucleus Counters / Dreiling, V. ; Haller, P. ; Helsper, C.; Kaminski, U. ; Plomp, A. ; Raes, F. ; Roth, C. ; Schier, J. ; Sch{\"u}rmann, G.},
  series = {Journal of Aerosol Science. 17 (1986), H. 3},
  journal   = {Journal of Aerosol Science. 17 (1986), H. 3},
  isbn      = {0021-8502},
  pages     = {565 -- 570},
  year      = {1986},
  language  = {en}
}
@article{HelsperMoelter1987,
  author    = {Helsper, Christoph and M{\"o}lter, W.},
  title     = {Determination and Neutralization of the Charge Produced by the Dispersion of Powders},
  series = {Journal of Aerosol Science. 18 (1987), H. 6},
  journal   = {Journal of Aerosol Science. 18 (1987), H. 6},
  isbn      = {0021-8502},
  pages     = {877 -- 880},
  year      = {1987},
  language  = {de}
}
@article{HelsperMoelterHaller1990,
  author    = {Helsper, Christoph and M{\"o}lter, W. and Haller, P.},
  title     = {Representative Dilution of Aerosols by a Factor of 10,000},
  series = {Journal of Aerosol Science. 21 (1990), H. Suppl. 1},
  journal   = {Journal of Aerosol Science. 21 (1990), H. Suppl. 1},
  isbn      = {0021-8502},
  pages     = {637 -- 640},
  year      = {1990},
  language  = {en}
}
@article{Helsper1986,
  author    = {Helsper, Christoph},
  title     = {Kondensationskernz{\"a}hler und ihre Anwendung in der Reinraumtechnik},
  series = {Swiss Chem. 8 (1986)},
  journal   = {Swiss Chem. 8 (1986)},
  isbn      = {0251-1703},
  pages     = {63 -- 66},
  year      = {1986},
  language  = {de}
}
@article{HelsperWiedensohlerWeiseetal.1986,
  author    = {Helsper, Christoph and Wiedensohler, A. and Weise, W. and L{\"u}tkemeier, E.},
  title     = {Determination of the Bipolar Charge Equilibrium in Pure Gases / Wiedensohler, A. ; Weise, W. ; Helsper, C. ; L{\"u}tkemeier, E.},
  series = {Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft f{\"u}r Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)},
  journal   = {Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft f{\"u}r Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)},
  publisher = {Pergamon Press},
  address   = {Oxford [u.a.]},
  pages     = {383 -- 386},
  year      = {1986},
  language  = {en}
}
@article{HelsperLuetkemeierWiedensohler1986,
  author    = {Helsper, Christoph and L{\"u}tkemeier, E. and Wiedensohler, A.},
  title     = {Charge Distribution by Unipolar Charging of Small Aerosol Particles / L{\"u}tkemeier, E. ; Helsper, C. ; Wiedensohler, A.},
  series = {Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft f{\"u}r Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)},
  journal   = {Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft f{\"u}r Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)},
  publisher = {Pergamon Press},
  address   = {Oxford [u.a.]},
  pages     = {474 -- 478},
  year      = {1986},
  language  = {en}
}
@article{Helsper1986,
  author    = {Helsper, Christoph},
  title     = {Measurement Techniques For Ultrafine Particles},
  series = {Ultrafine aerosols. Properties and behaviour. Proceedings of the 1. International Workshop on Ultrafine Aerosols of the Sonderforschungsbereich 209 'Stoff- und Energietransport in Aerosolen' -'Mass and energy transfer in aerosols'-, held at the Univ. of Duisburg on Sept. 29, 1986},
  journal   = {Ultrafine aerosols. Properties and behaviour. Proceedings of the 1. International Workshop on Ultrafine Aerosols of the Sonderforschungsbereich 209 'Stoff- und Energietransport in Aerosolen' -'Mass and energy transfer in aerosols'-, held at the Univ. of Duisburg on Sept. 29, 1986},
  address   = {Duisburg},
  year      = {1986},
  language  = {en}
}
@article{HelsperBartz1987,
  author    = {Helsper, Christoph and Bartz, H.},
  title     = {Theoretische Bestimmung des Abscheidegrades eines Filters bei verschiedenen Betriebszust{\"a}nden / Bartz, H. ; Helsper, C.},
  series = {Staub, Reinhaltung der Luft. 47 (1987)},
  journal   = {Staub, Reinhaltung der Luft. 47 (1987)},
  isbn      = {0039-0771},
  pages     = {112 -- 114},
  year      = {1987},
  language  = {de}
}
@article{Helsper1993,
  author    = {Helsper, Christoph},
  title     = {Integrit{\"a}tspr{\"u}fung an LF-Anlagen mit Hilfe von Pr{\"u}faerosolen},
  series = {Pharma-Technologie-Journal. 14 (1993), H. 2},
  journal   = {Pharma-Technologie-Journal. 14 (1993), H. 2},
  isbn      = {0931-9700},
  pages     = {36 -- 42},
  year      = {1993},
  language  = {de}
}
@article{Helsper1995,
  author    = {Helsper, Christoph},
  title     = {Probleme der Staubprobenahme bei der Filterpr{\"u}fung},
  series = {Filtrieren und Separieren (1995)},
  journal   = {Filtrieren und Separieren (1995)},
  isbn      = {0933-5927},
  pages     = {5 -- 13},
  year      = {1995},
  language  = {de}
}
@article{Helsper2002,
  author    = {Helsper, Christoph},
  title     = {Partikelmesstechnik},
  series = {Reinraumtechnik , Hrsg.: Gail, Lothar},
  journal   = {Reinraumtechnik , Hrsg.: Gail, Lothar},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {3-540-66885-3},
  pages     = {57 -- 82},
  year      = {2002},
  language  = {de}
}
@article{Helsper2003,
  author    = {Helsper, Christoph},
  title     = {Messverfahren zur Charakterisierung der Abscheidung luftgetragener Partikel in Filtern},
  series = {Schutzmaßnahmen vor mikrobiellen Belastungen des Innenraumes / VII. L{\"u}becker Fachtagung f{\"u}r Umwelthygiene. [Hrsg.:] Reinhard Keller ...},
  journal   = {Schutzmaßnahmen vor mikrobiellen Belastungen des Innenraumes / VII. L{\"u}becker Fachtagung f{\"u}r Umwelthygiene. [Hrsg.:] Reinhard Keller ...},
  publisher = {Inst. f. Medizinische Mikrobiologie u. Hygiene d. Med. Univ.},
  address   = {L{\"u}beck},
  pages     = {35 -- 61},
  year      = {2003},
  language  = {de}
}
@book{Hodapp1989,
  author    = {Hodapp, Josef},
  title     = {Die direkte Selbst-Regelung einer Asynchronmaschine mit einem Signalprozessor},
  publisher = {VDI-Verl.},
  address   = {D{\"u}sseldorf},
  isbn      = {3-18-147508-4},
  pages     = {II, 148 S. : graph. Darst.},
  year      = {1989},
  language  = {de}
}
@book{MeissenHotfilter1972,
  author    = {Meißen, Ralf and Hotfilter, Josef},
  title     = {Modell einer Einrichtung zur Positionierung von kugelf{\"o}rmigen Brennelementen nach einer Bohrung mit ber{\"u}hrungsloser fluidischer Abtastung / Josef Hotfilter ; Ralf Meißen},
  publisher = {Kernforschungsanlage},
  address   = {J{\"u}lich},
  pages     = {17 Bl.: graph. Darst.},
  year      = {1972},
  language  = {de}
}
@book{Meissen1975,
  author    = {Meißen, Ralf},
  title     = {Ein Meßsystem zur photometrischen Untersuchung reversibler und irreversibler photochemischer Reaktionen im Zeitbereich von 50 ns bis 5 ms},
  publisher = {Zentralbibl. d. KFA},
  address   = {J{\"u}lich},
  pages     = {III, 99 S.},
  year      = {1975},
  language  = {de}
}
@article{MeissenKrischer1978,
  author    = {Meißen, Ralf and Krischer, C.},
  title     = {Elektronische Fernsehlesehilfe f{\"u}r hochgradig sehbehinderte},
  series = {Biomedical Engineering / Biomedizinische Technik},
  volume    = {23},
  journal   = {Biomedical Engineering / Biomedizinische Technik},
  number    = {s1},
  publisher = {De Gruyter},
  address   = {Berlin},
  doi       = {10.1515/bmte.1978.23.s1.220},
  pages     = {220 -- 221},
  year      = {1978},
  language  = {de}
}
@book{Neubauer1991,
  author    = {Neubauer, Boris},
  title     = {Transkristalline Schichten auf Hochspannungskabeln aus Polyethylen : Struktur und Permeationseigenschaften},
  address   = {Darmstadt},
  pages     = {126 S. : Ill., graph. Darst.},
  year      = {1991},
  language  = {de}
}
@article{NeubauerJungnickel1993,
  author    = {Neubauer, Boris and Jungnickel, B. J.},
  title     = {Diffusion als Maß f{\"u}r die elektrische Isolier-Dauerfestigkeit von PE. L{\"a}ngs- und Querdiffusion durch transkristalline Oberfl{\"a}chenschichten},
  series = {Kunststoffe. 83 (1993), H. 3},
  journal   = {Kunststoffe. 83 (1993), H. 3},
  isbn      = {0023-5563},
  pages     = {231 -- 233},
  year      = {1993},
  language  = {de}
}
@article{HelsperMoelterMoelter1986,
  author    = {Helsper, Christoph and M{\"o}lter, W. and M{\"o}lter, L.},
  title     = {Korngr{\"o}ßenanalyseverfahren f{\"u}r trockene Pulver und St{\"a}ube von 0,5-25 µm},
  series = {Chemie-Technik. 16 (1986)},
  journal   = {Chemie-Technik. 16 (1986)},
  isbn      = {0340-9961},
  pages     = {140 -- 144},
  year      = {1986},
  language  = {de}
}
@article{HelsperMoelterWillemer1987,
  author    = {Helsper, Christoph and M{\"o}lter, W. and Willemer, W.},
  title     = {Fast and Automated Testing of Filter Media / M{\"o}lter, W. ; Helsper, C. ; Willemer, W.},
  series = {FILTECH Conference 1987 : Utrecht, Holland; September 23 - 25 1987 / org. by the Filtration Society , Vol. 1.},
  journal   = {FILTECH Conference 1987 : Utrecht, Holland; September 23 - 25 1987 / org. by the Filtration Society , Vol. 1.},
  publisher = {Filtration Society},
  address   = {Loughborough},
  pages     = {106 -- 112},
  year      = {1987},
  language  = {en}
}