@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},
}