@incollection{BERNHOLDKALINGLELLEK2012,
  author    = {T. BERNHOLD and N. KALING and M. LELLEK},
  title     = {Produktivit{\"a}tsmessung von Immobilien-Services - empirische Analyse und Status Quo},
  booktitle = {Facility Management Messe 2012 Tagungsband},
  isbn      = {978-3-8007-3417-7},
  year      = {2012},
}