@book{DellenBiernathErnst2001,
  author    = {Dellen, Richard and Biernath, J{\"u}rgen and Ernst, Raimund},
  title     = {Quo vadis Baubetrieb?},
  edition   = {1. Aufl.},
  publisher = {BFW-Bau},
  address   = {Dortmund},
  isbn      = {3-00-008465-7},
  pages     = {161 S. : Ill., graph. Darst.},
  year      = {2001},
  language  = {de}
}
@book{DellenUhlmann1996,
  author    = {Dellen, Richard and Uhlmann, Erich},
  title     = {Qualit{\"a}tsmanagement f{\"u}r Bauunternehmer und Planer},
  edition   = {1. Aufl.},
  publisher = {M{\"u}ller},
  address   = {K{\"o}ln},
  isbn      = {3-481-01044-3},
  pages     = {253 S. : Ill., graph. Darst.},
  year      = {1996},
  language  = {de}
}