1. a Global Health Sciences , University of California , San Francisco , USA
2. b Department of Epidemiology, Mailman School of Public Health , Columbia University , New York , USA
3. c Department of International Health, Johns Hopkins Bloomberg School of Public Health , Johns Hopkins University , Baltimore , USA
4. d Division of Epidemiology and Community Health , University of Minnesota School of Public Health , Minneapolis , USA
5. e International Planned Parenthood Federation , London , UK
6. f Department of Reproductive Health and Research , World Health Organization , Geneva , Switzerland
7. g United Nations Population Fund , New York , USA