@incollection{HelsperFissanFranzen1978,
  author    = {Helsper, Christoph and Fissan, H. J. and Franzen, H.},
  title     = {Particle Size Distributions of Combustion Aerosols},
  series = {Atmospheric Pollution 1978 : Proceedings of the 13th International Colloquium; 25-28 April 1978; Paris, France; Edited by Michel M. Benarie},
  booktitle = {Atmospheric Pollution 1978 : Proceedings of the 13th International Colloquium; 25-28 April 1978; Paris, France; Edited by Michel M. Benarie},
  editor    = {Benarie, Michel M.},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {0-444-41691-9},
  doi       = {10.1016/S0166-1116(08)71583-8},
  pages     = {263 -- 266},
  year      = {1978},
  abstract  = {It has been observed that carcinogenic polycyclic aromatic hydrocarbons (PAH) are present in the atmosphere. Combustion processes are considered the most important sources for PAH. Among these, the burning of coal produces the highest emission, but in cities with high traffic density and low meteorological exchange activities, vehicle emissions determine the immission situation, especially in narrow streets. For estimating the potential health effects caused by PAH, it is sufficient to characterize the emission of PAH with respect to their physical state, concentrations, and, as far as the particulate phase is concerned, size distribution. The size distribution is important for transport phenomena, inhalation, and deposition in the respiratory tract. These parameters mainly depend on the combustion system, on system operating conditions, on the exhaust system, and on exhaust cooling conditions. At exhaust-gas temperatures in the range of ambient air temperatures, almost the whole emission of PAH is made up of particulate matter.},
  language  = {en}
}
@book{HelsperFissanAhrens1979,
  author    = {Helsper, Christoph and Fißan, Heinz and Ahrens, Werner},
  title     = {Entwicklung eines Meßsystems zur direkten Bestimmung der Partikelgr{\"o}ßenverteilung von Aerosolen aus Verbrennungsvorg{\"a}ngen / Fißan, Heinz; Helsper, Christoph; Ahrens, Werner},
  publisher = {Westdeutscher Verl.},
  address   = {Opladen},
  isbn      = {3-531-02827-8},
  pages     = {47 S.: 14 graph. Darst.},
  year      = {1979},
  language  = {de}
}
@article{Helsper1979,
  author    = {Helsper, Christoph},
  title     = {Evaluation of Particle Size Distributions by Means of Particle Counters / Fißan, H. J. ; Helsper, C.},
  series = {Proceedings of the First Workshop of Particulate Control : 16. - 17. March 1978, Kernforschung-sanlage J{\"u}lich GmbH / prepared by U.S. Environmental Protection Agency, Off. of Research and Development, Washington, D.C, 1979,},
  journal   = {Proceedings of the First Workshop of Particulate Control : 16. - 17. March 1978, Kernforschung-sanlage J{\"u}lich GmbH / prepared by U.S. Environmental Protection Agency, Off. of Research and Development, Washington, D.C, 1979,},
  publisher = {Zentralbibliothek d. Kernforschungsanlage J{\"u}lich [in Komm.]},
  address   = {J{\"u}lich},
  pages     = {495 S.: Ill., graph. Darst.},
  year      = {1979},
  language  = {en}
}
@book{HelsperBesslingKiocketal.1979,
  author    = {Helsper, Christoph and Beßling, Harro and Kiock, R. and Fißan, H. J.},
  title     = {Experimentelle Untersuchung der Partikelanzahlkonzentration im Windkanal f{\"u}r den Einsatz von laseranemometrischen Verfahren / Beßling, Harro; Kiock, R.; Helsper, C.; Fißan, H. J.},
  publisher = {DFVLR},
  address   = {K{\"o}ln},
  pages     = {48 S.},
  year      = {1979},
  language  = {de}
}
@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}
}