@Book{Czymmek.2003,
  author = {Czymmek, Frank and Beuermann, Günter},
  title  = {Ökoeffizienz und unternehmerische Stakeholder},

  year   = {2003},
  number = {},
  url    = {http://www.gbv.de/dms/zbw/376078081.pdf},

  const  = {\ text}
}