@article{Hayford2010,
author = {Hayford, S. and Guzzo, K.},
title= {Age, relationship status, and the planning status of births},
year = {2010},
doi = {10.4054/DemRes.2010.23.13},
journal = {Demographic Research},
volume = {23},
number = {13},
pages = {365−398},
}