Kwek Kenneth, Yeap Min Li, Tan K H, Tee John C S, Yeo George S H
Division of Obstetrics and Gynecology, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore 229899.
Acta Obstet Gynecol Scand. 2005 Sep;84(9):914-5. doi: 10.1111/j.0001-6349.2005.00816.x.