@article{Lillard1993,
author = {Lillard, L.A. },
title= {Simultaneous equations for hazards: marriage duration and fertility timing},
year = {1993},
doi = {10.1016/0304-4076(93)90106-F},
journal = {Journal of Econometrics },
volume = {56},
number = {1–2},
pages = {189217},
}