Maskey MK, Baral KP, Shah R, Shrestha BD, Lang J, Rothman KJ. Field test results of the motherhood method to measure maternal mortality. Ind Med Gaz. 2011 Jan 1;133(1):64-9.
Nguyen USDT, Rothman KJ, Demissie S, Jackson DJ, Lang JM, Ecker JL. Transfers among women intending a birth center delivery in the San Diego birth center study. J Midwifery Womens Health. 2009 Mar 1;54(2):104-10.