@article{Simon:2007,
  author  = "U. Simon and S. Kübler and J. Boehner",
  title   = "Analysis of breeding bird communities along an urban-rural gradient in Berlin, Germany, by Hasse Diagram Technique",
  journal = "Urban Ecosystems",
  volume  = "Vol.10",
  number  = "no 1",
  pages   = "17--28",
  year    = "2007",
}