@article{Yang2006,
author = {Yang, Q. and Greenland, S. and Flanders, W.D.},
title= {Associations of maternal age- and parity-related factors with trends in low-birthweight rates: United States, 1980 through 2000},
year = {2006},
doi = {10.2105/AJPH.2004.049312},
journal = {American Journal of Public Health},
volume = {96},
number = {5},
pages = {856--861},
}