@misc{National Center for Health Statistics (NCHS)2011,
author = {National Center for Health Statistics (NCHS)},
title= {National Survey of Family Growth. 2006-2010 User’s Guide},
year = {2011},
URL = {http://www.cdc.gov/nchs/nsfg/nsfg_2006_2010_puf.htm},
address = {Hyattsville, MD},
}