@article{HelsperMoelterLoeffleretal.1993,
  author    = {Helsper, Christoph and M{\"o}lter, W. and L{\"o}ffler, F. and Wadenpohl, C.},
  title     = {Investigations on a New Aerosol Generator for the Production of Carbon Aggregate Particles / Helsper, C. ; M{\"o}lter, W. ; L{\"o}ffler, F. ; Wadenpohl, C. ; Kaufmann, S. ; Wenninger, G.},
  series = {Atmospheric Environment. Part A. General Topics. 27 A (1993), H. 8},
  journal   = {Atmospheric Environment. Part A. General Topics. 27 A (1993), H. 8},
  isbn      = {1352-2310},
  pages     = {1271 -- 1275},
  year      = {1993},
  language  = {en}
}
@article{HelsperHornSchneideretal.2008,
  author    = {Helsper, Christoph and Horn, Hans-Georg and Schneider, Friedhelm and Wehner, Birgit},
  title     = {Intercomparison of five mobility size spectrometers for measuring atmospheric submicrometer aerosol particles / Helsper, Christoph ; Horn, Hans-Georg ; Schneider, Friedhelm ; Wehner, Birgit ; Wiedensohler, Alfred},
  series = {Gefahrstoffe, Reinhaltung der Luft. Air Quality Control. 68 (2008), H. 11-12},
  journal   = {Gefahrstoffe, Reinhaltung der Luft. Air Quality Control. 68 (2008), H. 11-12},
  isbn      = {0949-8036},
  pages     = {475 -- 481},
  year      = {2008},
  language  = {en}
}