@article{SzaramowiczRoesslingJesseletal.2005,
  author    = {Szaramowicz, Martin and R{\"o}ßling, Holger and Jessel, Beate and Gall, Beate},
  title     = {Functions and functional units in ecologically oriented planning : tasks, state of the art and problems},
  isbn      = {3-931175-76-6},
  year      = {2005},
  language  = {en}
}