@misc{SponagelWachowitz1990,
  author    = {Sponagel, Stefan and Wachowitz, Waldemar},
  title     = {Wellendichtung : Offenlegungsschrift DE3830706A1 ; Ver{\"o}ffentlichungstag im Patentblatt: 22.03.1990 / Anmelder: Fa. Carl Freudenberg},
  publisher = {Deutsches Patent- und Markenamt},
  address   = {M{\"u}nchen},
  pages     = {4 S. : Ill.},
  year      = {1990},
  language  = {de}
}
@article{SponagelLutz1990,
  author    = {Sponagel, Stefan and Lutz, Th.},
  title     = {Ein Beitrag zur Bestimmung der Haertewerte von Elastomeren},
  series = {Kautschuk Gummi Kunststoffe. 43 (1990), H. 10},
  journal   = {Kautschuk Gummi Kunststoffe. 43 (1990), H. 10},
  isbn      = {0022-9520},
  pages     = {861 -- 865},
  year      = {1990},
  language  = {de}
}
@article{SponagelLutz1990,
  author    = {Sponagel, Stefan and Lutz, T.},
  title     = {Aggregatelager},
  series = {Kautschuk Gummi Kunststoffe. 43 (1990), H. 5},
  journal   = {Kautschuk Gummi Kunststoffe. 43 (1990), H. 5},
  isbn      = {0022-9520},
  pages     = {397 -- 406},
  year      = {1990},
  language  = {de}
}