- Correspondence to Dr Gurinder Tack, Respiratory Medicine, St Helens and Knowsley Teaching Hospitals NHS Trust, Prescot, UK;
- Received November 23, 2011
- Accepted January 19, 2012
- First published February 14, 2012.
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.