@inbook{Billiet2004,
author = {Billiet, J.  and Welkenhuysen-Gybels, J. },
title= {Assessing cross-national construct equivalence in the ESS: the case of six immigration items.},
year = {2004},
editor = {C., an Dijkum},
editor = {J., Blasius},
editor = {C., Durand},
booktitle = {C33 Sixth International Conference on Social Science Methodology: Recent Developments and Applications in Social Research Methodology},
address = {Amsterdam},
publisher = {Barbara Budrich Publisher:},
}