1. Nuffield Department of Women's & Reproductive Health John Radcliffe HospitalUniversity of Oxford Oxford UK
2. Fetal Medicine Unit Department of Maternal and Fetal Medicine Women's Center John Radcliffe HospitalOxford University Hospitals NHS Foundation Trust Oxford UK
3. Department of Epidemiology and Biostatistics College of Public Health University of Georgia Athens GA USA
4. Bodleian Health Care Libraries University of Oxford Oxford UK