@misc{Rydland2007,
author = {Rydland, L.T. and Sveinung, A. and Ǻ.G., Østensen},
title= {Contextual data for the European Social Survey. An overview and assessment of extant sources},
year = {2007},
URL = {http://www.europeansocialsurvey.org/docs/methodology/ESS_context_sources.pdf},
publisher = {Norwegian Social Science Data Services},
address = {Bergen},
}