@incollection{BERNHOLDKALINGLELLEK2011,
  author    = {T. BERNHOLD and N. KALING and V. LELLEK},
  title     = {Produktivit{\"a}tsmessung von Dienstleistungen},
  booktitle = {BERNHOLD, T.; GELLENBECK, K.; RIEMENSCHNEIDER, F., M{\"u}nsteraner Schriften zum Facility Management},
  year      = {2011},
}