8Lozano R, Naghavi M, Foreman K, et al. Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010:a systematic analysis for the Global Burden of Disease Study 2010[J]. Lancet,2012,380(9859):2095-2128..
9Hogan MC, Foreman KJ, Naghavi M, et al. Maternal mortality for 181 countries, 1980-2008:a systematic analysis of progress towards millennium development goal 5[J]. The Lancet,2010,375(9726):1609-1623..
10Clark SL, Belfort MA, Dildy GA,et al. Maternal death in the 21st century:causes, prevention, and relationship to cesarean delivery[J]. Am J Obstet Gynecol,2008,199(1):36.e1-.e5..
