@article{Dienst1977,
  author    = {Dienst, Karl-Jakob},
  title     = {Schnitt- und Zykelgeometrien},
  series = {Geometriae Dedicata (1977)},
  journal   = {Geometriae Dedicata (1977)},
  pages     = {23 -- 54},
  year      = {1977},
  language  = {de}
}
@book{Polumsky1977,
  author    = {Polumsky, Dieter},
  title     = {Analyse und Prognose des G{\"u}terverkehrs im Raum Mittelrhein / Rothschuh, Bruno [Mitarb.] ... Polumsky, Dieter [Mitarb.]},
  publisher = {Selbstverl.},
  address   = {Aachen},
  isbn      = {3-88354-057-9},
  pages     = {ca. 260 S.},
  year      = {1977},
  language  = {de}
}