Ranzini A C, Walters C A, Vintzileos A M
Department of Obstetrics and Gynecology and Reproductive Sciences, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, St. Peter's Medical Center, New Brunswick, USA.
Obstet Gynecol. 1999 May;93(5 Pt 2):854. doi: 10.1016/s0029-7844(98)00373-1.