Global, regional, and national levels and causes of maternal mortality during 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013
Author: Kassebaum, Nicholas J.  Published in: The Lancet, v. 384  no. 9947, pp. 980- 1004  Date: 2014
ISSN:  01406736,  DOI:  10.1016/S0140-6736(14)60696-6