@article{Welkenhuysen-Gybels2001,
author = {Welkenhuysen-Gybels, J. and Billiet, J.},
title= {The impact of third party presence in survey interviews on the measurement of political knowledge},
year = {2001},
doi = {10.1023/A:1016094700288},
volume = {36},
number = {3},
pages = {288--307},
}