@article{Hayford2008,
author = {Hayford, S.R.  and Morgan, S.P.},
title= {The quality of retrospective data on cohabitation},
year = {2008},
doi = {10.1353/dem.2008.0005},
journal = {Demography},
volume = {45},
number = {1},
pages = {129--141},
}