@article{Baizán2004,
author = {Baizán, P. and Aassve, A. and Billari, F.C.},
title= {The interrelations between cohabitation, marriage and first birth in Germany and Sweden},
year = {2004},
doi = {10.1023/B:POEN.0000039064.65655.3b},
volume = {25},
number = {6},
pages = {531--561},
}