@techreport{IrrekKristof2009,
  author    = {Irrek, Wolfgang and Kristof, Kora},
  title     = {Energie- und Materialeffizienz},
  institution = {Bundeszentrale f{\"u}r Politische Bildung},
  address   = {Bonn},
  year      = {2009},
  language  = {de}
}