@incollection{BERNHOLDKALINGLELLEK2012,
  author    = {BERNHOLD, T. and KALING, N. and LELLEK, V.},
  title     = {Productivity Measurement Model - A Holistic Approach For Services},
  series = {Proceedings of the 11th EuroFM Research Symposium, 24.-25. May 2012 in Copenhagen, Denmark, IN: JUNGHANS, A.; JENSEN, P. A. (Editors)},
  booktitle = {Proceedings of the 11th EuroFM Research Symposium, 24.-25. May 2012 in Copenhagen, Denmark, IN: JUNGHANS, A.; JENSEN, P. A. (Editors)},
  publisher = {Polyeknisk Forlag},
  address   = {Lyngby},
  pages     = {20 -- 30},
  year      = {2012},
  language  = {en}
}
@incollection{BECKERBERNHOLDBEVERUNGENetal.2013,
  author    = {BECKER, J. and BERNHOLD, T. and BEVERUNGEN, N. and KALING, N. and KNACKSTEDT, R. and LELLEK, V. and RAUER, H.},
  title     = {Softwaregest{\"u}tzte Konstruktion von Produktivit{\"a}tsmodellen im Facility Management},
  series = {THOMAS, O.; N{\"U}TTGENS, M. (Hrsg.): Dienstleistungsmodellierung 2012, Product-Service Systems und Produktivit{\"a}t},
  booktitle = {THOMAS, O.; N{\"U}TTGENS, M. (Hrsg.): Dienstleistungsmodellierung 2012, Product-Service Systems und Produktivit{\"a}t},
  edition   = {1},
  publisher = {Springer Gabler},
  address   = {Wiesbaden},
  isbn      = {978-3-658-00862-8},
  pages     = {208 -- 226},
  year      = {2013},
  language  = {de}
}
@misc{BERNHOLDLELLEKKUeRSCHNERetal.2013,
  author    = {BERNHOLD, T. and LELLEK, V. and K{\"U}RSCHNER, M. and AVERBECK, A.-K.},
  title     = {Productivity Measurement of Facility Services - A web-based CAFM Application; XXIII International RESER Conference; September 19th-21st 2013, Aix en Provence},
  year      = {2013},
  language  = {en}
}
@misc{BERNHOLDLELLEKKOERSetal.2014,
  author    = {BERNHOLD, T. and LELLEK, V. and KOERS, J. and YOUSSEF, L.},
  title     = {International RESER Conference: Visualization of services - Closing expectations gaps and increasing service quality, XXIV. RESER Conference, 11.-13. September 2014, Helsinki, Finnland},
  pages     = {S. 900 -- 911},
  year      = {2014},
  language  = {en}
}
@incollection{BERNHOLDLELLEK2014,
  author    = {BERNHOLD, T. and LELLEK, V.},
  title     = {Produktivit{\"a}tsmessung von Immobiliendienstleistungen: Theorie - Konzepte - Praxis},
  series = {BERNHOLD, T.; MAY, M.; MEHLIS, J.; Handbuch Facility Management: Grundlagen, Arbeitsfelder, Wissensmanagement; 42. Erg{\"a}nzungslieferung},
  booktitle = {BERNHOLD, T.; MAY, M.; MEHLIS, J.; Handbuch Facility Management: Grundlagen, Arbeitsfelder, Wissensmanagement; 42. Erg{\"a}nzungslieferung},
  publisher = {ecomed SICHERHEIT},
  address   = {Heidelberg, M{\"u}nchen, Landsberg, Frechen, Hamburg},
  pages     = {1 -- 29 (2.2.1.1.1)},
  year      = {2014},
  language  = {de}
}
@misc{LELLEKBERNHOLD2015,
  author    = {LELLEK, V. and BERNHOLD, T.},
  title     = {Productivity Measurement of Service - Models and Web-based Computer Applications; 3rd International Conference on Management, Leadership and Governance - ICMLG 2015, 12-13 February 2015, Auckland, New Zealand.},
  year      = {2015},
  language  = {en}
}
@incollection{BERNHOLDKALINGLELLEK2012,
  author    = {BERNHOLD, T. and KALING, N. and LELLEK, V.},
  title     = {Productivity Measurement Model - A Holistic Approach For Services},
  series = {JUNGHANS, A.; JENSEN, P. A (Editors) Proceedings of the 11th EuroFM Research Symposium, 24.-25. May 2012 in Copenhagen, Denmark},
  booktitle = {JUNGHANS, A.; JENSEN, P. A (Editors) Proceedings of the 11th EuroFM Research Symposium, 24.-25. May 2012 in Copenhagen, Denmark},
  publisher = {Polyeknisk Forlag 2012},
  address   = {Lyngby :},
  pages     = {20 -- 30},
  year      = {2012},
  language  = {en}
}
@article{BECKERBERNHOLDBEVERUNGENetal.2012,
  author    = {BECKER, J. and BERNHOLD, T. and BEVERUNGEN, D. and KALING, N. and KNACKSTEDT, R. and LELLEK, V. and RAUER, H. P.},
  title     = {Construction of Productivity Models: A Tool Supported Approach in the Area of Facility Management},
  series = {Enterprise Modelling and Information Systems Architectures},
  volume    = {7},
  journal   = {Enterprise Modelling and Information Systems Architectures},
  number    = {1},
  doi       = {10.18417/emisa.7.1.2},
  pages     = {26 -- 40},
  year      = {2012},
  language  = {en}
}
@incollection{BECKERBERNHOLDBEVERUNGENetal.2013,
  author    = {BECKER, J. and BERNHOLD, T. and BEVERUNGEN, D. and KALING, N. and KNACKSTEDT, R. and LELLEK, V. and RAUER, H.},
  title     = {Softwaregest{\"u}tzte Konstruktion von Produktivit{\"a}tsmodellen im Facility Management},
  series = {Thomas, Oliver; N{\"u}ttgens, Markus (Hg.): Dienstleistungsmodellierung 2012. Product-Service Systems und Produktivit{\"a}t.},
  booktitle = {Thomas, Oliver; N{\"u}ttgens, Markus (Hg.): Dienstleistungsmodellierung 2012. Product-Service Systems und Produktivit{\"a}t.},
  publisher = {Springer},
  address   = {Wiesbaden},
  pages     = {208 -- 226},
  year      = {2013},
  language  = {de}
}
@misc{LELLEKAVERBECK2013,
  author    = {LELLEK, V. and AVERBECK, A.},
  title     = {Creation of value for guest - measuringof Facility Services in hotels including the customer value. In: Proceedings of the 15th Facility \& Real Estate Management Congress, 6. - 8. February 2013, Hotel and leisure facilities, Kufstein.},
  year      = {2013},
  language  = {en}
}