@article{Zimmermann2006,
author = {Zimmermann, A.C. and Easterlin, R.A.},
title= {Happily ever after? Cohabitation, marriage, divorce, and happiness in Germany},
year = {2006},
doi = {10.1111/j.1728-4457.2006.00135.x},
journal = {Population and Development Review},
volume = {32},
number = {3},
pages = {511--528},
}