1.
International Social Survey Programme 2001 (Netherlands)
2.
EVS - European Values Study 1999 - Belgien ; EVS - European Values Study 1999 - Belgium
3.
4.
5.
EVS - European Values Study 1999 - Luxemburg ; EVS - European Values Study 1999 - Luxembourg
EVS - European Values Study 1999 - Niederlande ; EVS - European Values Study 1999 - Netherlands