@book{Call1997,
  author    = {Call, Guido},
  title     = {Entstehung und Markteinf{\"u}hrung von Produktneuheiten},
  publisher = {Gabler},
  address   = {Wiesbaden},
  isbn      = {3409136975},
  pages     = {XX, 290 S.: graph. Darst.},
  year      = {1997},
  language  = {de}
}
@book{BiselliBornSchroederetal.1997,
  author    = {Biselli, Manfred and Born, Christoph and Schr{\"o}der, Bernd and Wandrey, Christian},
  title     = {Reaktor f{\"u}r die Zellkulturtechnik mit blasenfreier Begasung},
  pages     = {10 S.},
  year      = {1997},
  language  = {de}
}
@book{BergmannSchaeferBlomeetal.1997,
  author    = {Bergmann, Ludwig and Sch{\"a}fer, Clemens and Blome, Hans-Joachim and Gobrecht, Heinrich},
  title     = {Lehrbuch der Experimentalphysik ; Bd. 8 : Sterne und Weltraum},
  editor    = {Raith, Wilhelm},
  publisher = {de Gruyter},
  address   = {Berlin [u.a.]},
  isbn      = {3110151731},
  pages     = {XII, 467 S : Ill., graph. Darst.},
  year      = {1997},
  language  = {de}
}