@incollection{BERNHOLDKALINGLELLEK2012,
  author    = {BERNHOLD, T. and KALING, N. and LELLEK, M.},
  title     = {Produktivit{\"a}tsmessung von Immobilien-Services - empirische Analyse und Status Quo},
  series = {Facility Management Messe 2012 Tagungsband},
  booktitle = {Facility Management Messe 2012 Tagungsband},
  publisher = {VDE Verlag},
  address   = {Berlin, Offenbach},
  isbn      = {978-3-8007-3417-7},
  pages     = {157 -- 170},
  year      = {2012},
  language  = {de}
}
@misc{BERNHOLDKALINGLELLEK2011,
  author    = {BERNHOLD, T. and KALING, N. and LELLEK, M.},
  title     = {Measurement of productivity of property services: an empiric analysis of the status quo, XXI. International RESER Conference, Hamburg, 07.09.-10.09.2011},
  year      = {2011},
  language  = {en}
}
@incollection{BERNHOLDKALINGLELLEK2011,
  author    = {BERNHOLD, T. and KALING, N. and LELLEK, M.},
  title     = {Produktivit{\"a}tsmessung von Dienstleistungen},
  series = {BERNHOLD, T.; GELLENBECK, K.; RIEMENSCHNEIDER, F., M{\"u}nsteraner Schriften zum Faclity Management},
  booktitle = {BERNHOLD, T.; GELLENBECK, K.; RIEMENSCHNEIDER, F., M{\"u}nsteraner Schriften zum Faclity Management},
  publisher = {INFA-ISFM e.V.},
  address   = {M{\"u}nster, Ahlen},
  isbn      = {978-3-00-036210-1},
  pages     = {108 -- 122},
  year      = {2011},
  language  = {de}
}
@misc{BECKERBERNHOLDBEVERUNGENetal.2012,
  author    = {BECKER, J. and BERNHOLD, T. and BEVERUNGEN, D. and KALING, N. and KNACKSTEDT, R. and LELLEK, M. and RAUER, H.},
  title     = {Softwaregest{\"u}tzte Konstruktion von Produktivit{\"a}tsmodellen im Facility Management, Dienstleistungsmodellierung 2012 (DLM 2012); 3. Workshop im Rahmen der Modellierung 2012, 14.-15. M{\"a}rz 2012, Otto-Friedrich-Universit{\"a}t Bamberg},
  year      = {2012},
  language  = {de}
}
@incollection{BERNHOLDKALINGLELLEK2011,
  author    = {BERNHOLD, T. and KALING, N. and LELLEK, M.},
  title     = {Measurement of productivity of property services - an empiric analysis of the status quo},
  series = {GANZ, W.; KIRCHERER, F.; SCHLETZ, A. (Hrsg.); Productivity of Services NextGen - Beyond Output/Input},
  booktitle = {GANZ, W.; KIRCHERER, F.; SCHLETZ, A. (Hrsg.); Productivity of Services NextGen - Beyond Output/Input},
  edition   = {1. Aufl.},
  publisher = {Fraunhofer Verlag},
  address   = {Stuttgart},
  isbn      = {978-3-8396-0297-3},
  pages     = {190 -- 191},
  year      = {2011},
  language  = {en}
}