@article{Schoen2003,
author = {Schoen, R.  and Tufis, P. },
title= {Precursors of nonmarital fertility in the United States},
year = {2003},
doi = {10.1111/j.1741-3737.2003.01030.x},
journal = {Journal of Marriage and Family },
volume = {65},
number = {4},
pages = {1030--1040},
}