Levens Eric D, Scheinberg Phillip, DeCherney Alan H
Reproductive Endocrinology and Infertility, National Institutes of Health, Walter Reed Army Medical Center, National Naval Medical Center, Uniformed Services University of the Health Sciences, Maryland, USA.
Obstet Gynecol. 2007 Oct;110(4):913-7. doi: 10.1097/01.AOG.0000279138.64895.2b.