@book{Kettern1993,
  author    = {Kettern, J{\"u}rgen},
  title     = {Mechanical and biological treatment of waste after separate collection / R. Damiecki; J.T. Kettern. Italian Ministry of Enviroment},
  publisher = {Eigenverlag},
  address   = {Caglieri},
  pages     = {16 S.},
  year      = {1993},
  language  = {en}
}