@article{Wiik2012,
author = {Wiik, K.A. and Keizer, R. and Lappegård, T. },
title= {Relationship quality in marital and cohabiting unions across Europe},
year = {2012},
doi = {10.1111/j.1751-3737.2012.00967x},
journal = {Journal of Marriage and Family },
volume = {47},
pages = {389--398},
}