- Correspondence to Dr Joseph R DiFranza, Department of Family Medicine and Community Health, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts, 01655, USA;
- Received March 1, 2011
- Accepted May 31, 2011
- First published June 28, 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.