1. WHO, UNICEF, UNFPA, The World Bank. Trends in maternal mortality: 1990 to 2010. WHO, UNICEF, UNFPA, and The World Bank Estimates, 2012.
2. Global Strategy for Women's and Children's Health,2010
3. WHO, UNICEF, UNFPA, The World Bank. Trends in maternal mortality: 1990 to 2008. WHO, UNICEF, UNFPA, and The World Bank Estimates, 2010.
4. Maternal mortality for 181 countries, 1980–2008: a systematic analysis of progress towards Millennium Development Goal 5;Hogan;Lancet,2010
5. Maternal deaths drop by one-third from 1990 to 2008: a United Nations analysis;Wilmoth;Bull World Health Organ,2010