@article{Hellmer2009,
  author    = {Fritz Hellmer},
  title     = {Wirtschaftscluster},
  journal   = {Geographische Revue: Zeitschrift f{\"u}r Literatur und Diskussion},
  volume    = {6},
  number    = {1},
  pages     = {27 -- 37},
  year      = {2009},
}