@book{Schlageter.1983,
  address = {Stuttgart},
  author = {Schlageter, Gunter},
  edition = {2., neubearb. und erw. Aufl.},
  interhash = {d7cd6c24fdb50303672c2fc9a188947b},
  intrahash = {a4b06084886bfb49ae6302374fffdf08},
  isbn = {3519123398},
  publisher = {Teubner},
  title = {Datenbanksysteme:  Konzepte und Modelle ; mit einigen Tabellen und zahlreichen Beispielen},
  year = 1983
}

@book{Gabriel.1994,
  address = {Berlin},
  author = {Gabriel, Roland and R\"ohrs, Heinz-Peter},
  interhash = {6963ff208a74e500baa5c38d6234c803},
  intrahash = {93aaf899f785659d1f8a5d1f106d9a6c},
  isbn = {3540576959},
  publisher = {Springer},
  title = {Datenbanksysteme:  Konzeptionelle Datenmodellierung und Datenbankarchitekturen},
  year = 1994
}

@book{Schafer.1986,
  address = {Bergisch Gladbach},
  author = {Schäfer, Gunter},
  interhash = {c0e21b34f2c6a041a7ddd4a2415afc99},
  intrahash = {6a92f9d8629d8ee1ff7bf477aeae7e34},
  isbn = {3890120539},
  publisher = {Eul},
  series = {Reihe},
  title = {Entwurf logischer Datenstrukturen für konzeptionelle Schemata von Datenbanken},
  volume = 12,
  year = 1986
}

@book{Elmasri.2001,
  address = {Reading, Mass.},
  author = {Elmasri, Ramez and Navathe, B. Shamkant},
  edition = {3. ed., internat. ed., [Nachdr.]},
  interhash = {5924cd4bac30788d33ef3b97aeb4530e},
  intrahash = {037d0c2f487455749d3b510f4677e6a2},
  isbn = {0201542633},
  publisher = {Addison-Wesley},
  title = {Fundamentals of database systems},
  year = 2001
}