@article{SponagelKilthauSpies1987,
  author    = {Sponagel, Stefan and Kilthau, G. and Spies, K. H.},
  title     = {Sealing mechanism of lip seals},
  series = {Eleventh 11th International Conference on Fluid Sealing : proceedings of the 11th Internat. Conference on Fluid Sealing, held at Cannes, France 8 - 10 April, 1987 / organised and sponsored by BHRA, the Fluid Engineering Centre. Ed. B. S. Nau},
  journal   = {Eleventh 11th International Conference on Fluid Sealing : proceedings of the 11th Internat. Conference on Fluid Sealing, held at Cannes, France 8 - 10 April, 1987 / organised and sponsored by BHRA, the Fluid Engineering Centre. Ed. B. S. Nau},
  publisher = {Elsevier},
  address   = {London},
  isbn      = {3-540-51383-3},
  pages     = {748 -- 772},
  year      = {1987},
  language  = {en}
}
@article{SponagelUngerSpies2003,
  author    = {Sponagel, Stefan and Unger, J. and Spies, K. H.},
  title     = {H{\"a}rtebegriff im Zusammenhang mit Vernetzung, Bruchdehnung und Dauerfestigkeit eines Elastomers},
  series = {Kautschuk Gummi Kunststoffe. 56 (2003), H. 11},
  journal   = {Kautschuk Gummi Kunststoffe. 56 (2003), H. 11},
  isbn      = {0948-3276},
  pages     = {608 -- 613},
  year      = {2003},
  language  = {de}
}