@article{Frost2007,
author = {Frost, J.J. and Singh, S. and Finer, L.B.},
title= {Factors Associated with Contraceptive Use and Nonuse, United States, 2004},
year = {2007},
doi = {10.1363/3909007},
journal = {Perspectives on Sexual and Reproductive Health},
volume = {39},
pages = {90--99},
}