@article{Singer2013,
  author    = {Rudolf Singer},
  title     = {Der Frauenschuh (Cypripedium calceolus L.)},
  journal   = {Ver{\"o}ffentlichungen des Naturkundlichen Vereins Egge-Weser},
  volume    = {15},
  pages     = {65 -- 66},
  year      = {2013},
}