@incollection{Welfens2003,
  author    = {Welfens, Maria J.},
  title     = {{\"O}kologischer Rucksack},
  booktitle = {{\"O}ko-Lexikon},
  editor    = {Simonis, Udo E.},
  publisher = {Beck},
  address   = {M{\"u}nchen},
  pages     = {152},
  year      = {2003},
  language  = {de}
}