- Correspondence to Dr David Armstrong, Department of Respiratory and Sleep Medicine, Royal Hospital for Sick Children, 9 Sciennes Road, Edinburgh, EH9 1LF, UK;
- Received September 25, 2013
- Revised December 16, 2013
- Accepted December 30, 2013
- First published January 24, 2014.
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.