Core state preconception health indicators - pregnancy risk assessment monitoring system and behavioral risk factor surveillance system, 2009.
Robbins CL, Zapata LB, Farr SL, Kroelinger CD, Morrow B, Ahluwalia I, D'Angelo DV, Barradas D, Cox S, Goodman D, et al. MMWR Surveill Summ. 2014 Apr 25; 63(3):1-62.