Ananth Cande V, Demissie Kitaw, Kramer Michael S, Vintzileos Anthony M
Department of Obstetrics, Gynecology and Reproductive Sciences, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School/Saint Peter's University Hospital, New Brunswick 08901-1977, USA.
Am J Public Health. 2003 Apr;93(4):577-9. doi: 10.2105/ajph.93.4.577.