Bun Cheung Yin, Yip Paul, Karlberg Johan
Clinical Trials Centre, Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong, China. Department of Paediatrics, University of Hong Kong, Pokfulam, Hong Kong, China. Department of Statistics and Actuarial Sciences, University of Hong Kong, Pokfulam, Hong Kong, China.
Am J Epidemiol. 2000 Dec 15;152(12):1120. doi: 10.1093/aje/152.12.1120.