1. Maternal deaths averted by contraceptive use: an analysis of 172 countries;Ahmed;Lancet,2012
2. Adding it up: costs and benefits of contraceptive services—estimates for 2012;Singh,2012
3. Trends in maternal mortality: 1990 to 2010. WHO, UNICEF, UNFPA and The World Bank estimates,2012
4. Averting Maternal Death and Disability (AMDD). Monitoring emergency obstetric care: a handbook,2009
5. Maternal death surveillance and response;Danel;Bull World Health Organ,2011