@article{HelsperWiedensohlerLuetkemeieretal.2006,
  author    = {Christoph Helsper and A. Wiedensohler and E. L{\"u}tkemeier and M. Feldpausch},
  title     = {Investigation on the Bipolar Charge Distribution at Various Gas Conditions / Wiedensohler, A.; L{\"u}tkemeier, E.; Feldpausch, M. ; Helsper, C.},
  journal   = {Journal of Aerosol Science. 17 (1986), H. 3},
  pages     = {413 -- 416},
  year      = {2006},
}