Podczaski Edward, Cain Joanna
Department of Obstetrics and Gynecology, The Pennsylvania State University School of Medicine, The Milton S Hershey Medical Center, Hershey 17033, USA.
Clin Obstet Gynecol. 2002 Sep;45(3):928-38. doi: 10.1097/00003081-200209000-00038.