Vogel J P, Betrán A P, Gülmezoglu A M
UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
BJOG. 2015 Apr;122(5):700. doi: 10.1111/1471-0528.13266. Epub 2015 Jan 5.