- Correspondence to Professor Kun-Yang Chuang, School of Public Health, Taipei Medical University, 250 Wu Hsing Street, Taipei 110, Taiwan;
- Accepted July 5, 2011
- First published August 31, 2011.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.