Wu R T, Shyu M K, Lee C N, Wu C C, Hwa H L, Lin C J, Chen F C, Chang L S, Pan M F, Tseng L H
Department of Obstetrics and Gynecology, College of Medicine, National Taiwan University, Taipei.
J Ultrasound Med. 1995 Jul;14(7):555-8. doi: 10.7863/jum.1995.14.7.555.