Sepulveda W, Berry S M, Romero R, King M E, Johnson M P, Cotton D B
Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Hutzel Hospital, Detroit, Michigan 48201.
J Ultrasound Med. 1993 Dec;12(12):761-6. doi: 10.7863/jum.1993.12.12.761.