@book{Gerhardt1994,
  author    = {Gerhardt, Hans Joachim},
  title     = {Absaugung von großfl{\"a}chig austretenden Schadstoffen beim offenen Guttransport},
  address   = {Frankfurt/M},
  year      = {1994},
  language  = {de}
}
@article{Gerhardt1994,
  author    = {Gerhardt, Hans Joachim},
  title     = {Lufttechnische Pr{\"u}fungen von Abz{\"u}gen - Kritische Anmerkungen zur Pr{\"u}fvorschrift DIN 12 924 Teil 1},
  series = {GIT Spezial: Arbeitschutz (1994)},
  journal   = {GIT Spezial: Arbeitschutz (1994)},
  isbn      = {0940-032X},
  pages     = {90 -- 95},
  year      = {1994},
  language  = {de}
}
@article{Gerhardt1994,
  author    = {Gerhardt, Hans Joachim},
  title     = {L{\"o}sungskonzept zur Bel{\"u}ftung von Rottehallen},
  series = {Abfallwirtschaftsjournal. 6 (1994), H. 10},
  journal   = {Abfallwirtschaftsjournal. 6 (1994), H. 10},
  isbn      = {0934-6422},
  pages     = {689 -- 692},
  year      = {1994},
  language  = {de}
}
@article{Gerhardt1995,
  author    = {Gerhardt, Hans Joachim},
  title     = {Arbeitsschutz in Altstoffsortieranlagen - Raumlufttechnische Maßnahmen},
  series = {Abfallwirtschaftsjournal. 7 (1995), H. 7/8},
  journal   = {Abfallwirtschaftsjournal. 7 (1995), H. 7/8},
  isbn      = {0934-6422},
  pages     = {471 -- 473},
  year      = {1995},
  language  = {de}
}
@article{Siedenbiedel1999,
  author    = {Siedenbiedel, Georg},
  title     = {Unternehmenspr{\"a}senz am Auslandsmarkt},
  series = {Business-to-Business-Marketing : Handbuch f{\"u}r Vertrieb, Technik, Service / Werner Pepels (Hrsg.)},
  journal   = {Business-to-Business-Marketing : Handbuch f{\"u}r Vertrieb, Technik, Service / Werner Pepels (Hrsg.)},
  publisher = {Luchterhand},
  address   = {Neuwied [u.a.]},
  pages     = {630 -- 646},
  year      = {1999},
  language  = {de}
}
@book{Siedenbiedel2001,
  author    = {Siedenbiedel, Georg},
  title     = {Organisationslehre},
  publisher = {Kohlhammer},
  address   = {Stuttgart [u.a.]},
  isbn      = {3-17-016498-8},
  pages     = {XVI, 239 S. : graph. Darst.},
  year      = {2001},
  language  = {de}
}
@book{SiedenbiedelEislerMertz2000,
  author    = {Siedenbiedel, Georg and Eisler-Mertz, Christiane},
  title     = {Schl{\"u}sselqualifikationen im Marketing},
  publisher = {Fortis [u.a.]},
  address   = {K{\"o}ln [u.a.]},
  pages     = {281 S. : Ill., graph. Darst.},
  year      = {2000},
  language  = {de}
}
@article{Siedenbiedel2000,
  author    = {Siedenbiedel, Georg},
  title     = {Der Auslandsabsatz als Gegenstand strategischer Entscheidungen},
  series = {Marketing-Management f{\"u}r Ingenieure und Informatiker /Pepels. Werner (Hrsg.)},
  journal   = {Marketing-Management f{\"u}r Ingenieure und Informatiker /Pepels. Werner (Hrsg.)},
  publisher = {Fortis [u.a.]},
  address   = {K{\"o}ln [u.a.]},
  pages     = {207 -- 234},
  year      = {2000},
  language  = {de}
}
@book{Tietze1992,
  author    = {Tietze, J{\"u}rgen},
  title     = {Monotonie und Kr{\"u}mmung : Wechselbeziehungen bei Gesamtkosten- und St{\"u}ckkostenfunktionen},
  publisher = {Alano-Verl.},
  address   = {Aachen},
  isbn      = {3-89399-169-7},
  pages     = {VI, 51 S. : zahlr. graph. Darst.},
  year      = {1992},
  language  = {de}
}
@book{Tietze1992,
  author    = {Tietze, J{\"u}rgen},
  title     = {{\"O}konomische Interpretation optimaler Simplex-Tableaus},
  publisher = {Alano-Verl.},
  address   = {Aachen},
  isbn      = {3-89399-170-0},
  pages     = {VI, 33 S.},
  year      = {1992},
  language  = {de}
}