@article{BergerEngels2012,
  author    = {Martin Berger and Wolf Engels},
  title     = {Die ornithologischen Tageb{\"u}cher von Helmut Sick (1910 - 1991)},
  journal   = {Vogelwarte : Zeitschrift f{\"u}r Vogelkunde},
  volume    = {49},
  number    = {2},
  pages     = {79 -- 83},
  year      = {2012},
}