@book{TorneyPurtaLehmannOswaldetal.2001,
  author    = {Judith Torney-Purta and Rainer Lehmann and Hans Oswald and Wolfram Schulz},
  title     = {Citizenship and education in twenty-eight countries : civic knowledge at age fourteen},
  isbn      = {90-5166-834-1},
  year      = {2001},
}