@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 = {189--217},
}