@article{Martin2013,
author = {Martin, J.A. and Hamilton, B.E. and Osterman, M.J.K. and Curtin, S.C. and Mathews, T.J. },
title= {Births: Final Data for 2012},
year = {2013},
journal = {National Vital Stat. Reports },
volume = {62},
number = {9},
pages = {1--87},
}