Lam Helena, Lo Tsz-Kin, Lau Elizabeth, Chin Robert, Tang Lawrence
Fetal Medicine Unit, Department of Obstetrics and Gynecology, Kwong Wah Hospital, 25 Waterloo Rd, Kowloon, Hong Kong.
J Ultrasound Med. 2006 Nov;25(11):1481-4. doi: 10.7863/jum.2006.25.11.1481.