@misc{BerndtHoeckerKuropkaetal.1990,
  author    = {Berndt, Heinz and H{\"o}cker, Hartwig and Kuropka, Rolf and Kinkel, Joachim},
  title     = {Silanderivate : Europ{\"a}ische Patenschrift / Offenlegungsschrift},
  publisher = {Europ{\"a}isches Patentamt / Deutsches Patent- und Markenamt},
  address   = {Den Hague / M{\"u}nchen},
  pages     = {10 S. / 13 S. : graph. Darst.},
  year      = {1990},
  language  = {de}
}
@misc{BerndtHoeckerKuropkaetal.1991,
  author    = {Berndt, Heinz and H{\"o}cker, Hartwig and Kuropka, Rolf and Kinkel, Joachim},
  title     = {Silane coated inorganic materials for chromatography : United States Patent},
  publisher = {[The United States Patent and Trademark Office]},
  address   = {[Alexandria, VA u.a.]},
  pages     = {9 S. : graph. Darst.},
  year      = {1991},
  language  = {en}
}