- Correspondence to Dr Pamela M Ling, University of California, San Francisco, Center for Tobacco Control Research and Education, 350 Parnassus Avenue suite 366, San Francisco, CA 94143-1390, USA;
- Received April 22, 2014
- Accepted November 25, 2014
- First published January 6, 2015.
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.