@misc{SponagelGrafGross1987,
  author    = {Sponagel, Stefan and Graf, G{\"u}nter and Groß, Heinz},
  title     = {Verfahren zur Herstellung eines Dichtringes : Patentschrift DE3621242C1 ; Ver{\"o}ffentlichungstag der Patenterteilung : 25.06.1987 / Anmelder: Fa. Carl Freudenberg. Erfinder: G{\"u}nter Graf ; Heinz Groß ; Stefan Sponagel},
  publisher = {Deutsches Patent- und Markenamt},
  address   = {M{\"u}nchen},
  pages     = {5 S. : Ill.},
  year      = {1987},
  language  = {de}
}
@book{SponagelWachowitz1993,
  author    = {Sponagel, Stefan and Wachowitz, Waldemar},
  title     = {Wellendichtung : Europ{\"a}ische Patentschrift DE3621242C1 ; Ver{\"o}ffentlichungstag der Patentschrift : 06.06.1993 / Anmelder: Fa. Carl Freudenberg},
  publisher = {Europ{\"a}isches Patentamt},
  address   = {[M{\"u}nchen u.a.]},
  pages     = {5 S. : Ill.},
  year      = {1993},
  language  = {de}
}
@article{SponagelUnger1998,
  author    = {Sponagel, Stefan and Unger, J.},
  title     = {Organisation und Strukturierung technischer Messungen},
  series = {Werkstattstechnik. 88 (1998), H. 5},
  journal   = {Werkstattstechnik. 88 (1998), H. 5},
  isbn      = {1436-5006},
  pages     = {223 -- 226},
  year      = {1998},
  language  = {de}
}
@article{StaatKuehnHaugeretal.2004,
  author    = {Staat, Manfred and K{\"u}hn, R. and Hauger, W. and Sponagel, Stefan},
  title     = {An Interpretation of Wolff's Law},
  series = {Biomedizinische Technik. 49 (2004)},
  journal   = {Biomedizinische Technik. 49 (2004)},
  isbn      = {0932-4666},
  pages     = {1020 -- 1021},
  year      = {2004},
  language  = {de}
}