@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}
}