@article{Billy1992,
author = {Billy, J.O.G. and Moore, D.E.},
title= {A multilevel analysis of marital and nonmarital fertility in the United-States},
year = {1992},
doi = {10.1093/sf/70.4.977},
journal = {Social Forces},
volume = {70},
number = {4},
pages = {977--1011},
}