@book{WollertFiedler1998,
  author    = {Wollert, J{\"o}rg and Fiedler, J{\"o}rg},
  title     = {Automatisieren mit dem PC. - 2. Aufl.},
  edition   = {2. Aufl.},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {3-540-63271-9},
  pages     = {IX, 343 S.},
  year      = {1998},
  language  = {de}
}
@book{PfeifferKnepper1998,
  author    = {Pfeiffer, Johann and Knepper, Ludger},
  title     = {Diplom Ingenieur/Diplom Ingenieurin (Fachhochschule) Maschinenbau Konstruktionstechnik},
  publisher = {Bertelsmann},
  address   = {Bielefeld},
  pages     = {Losebl.-Ausg.},
  year      = {1998},
  language  = {de}
}
@book{KnepperPfeiffer1998,
  author    = {Knepper, Ludger and Pfeiffer, Johann},
  title     = {Diplom-Ingenieur/Diplom-Ingenieurin (Fachhochschule) Maschinenbau Konstruktionstechnik},
  publisher = {Bertelsmann},
  address   = {Bielefeld},
  pages     = {Loseblattausg.},
  year      = {1998},
  language  = {de}
}
@book{GartzenHeilMang1998,
  author    = {Gartzen, Johannes and Heil, G{\"u}nter and Mang, Thomas},
  title     = {Verfahren zur Aufbereitung eines Gemisches aus Zellulose und granuliertem Polymer / Patentschrift DE 4133699 C2},
  publisher = {Deutsches Patentamt},
  address   = {M{\"u}nchen},
  pages     = {4 S.},
  year      = {1998},
  language  = {de}
}