1. Global Initiative for Asthma. Global strategy for asthma management and prevention. National Institutes of Health. National Heart, Lung, and Blood Institute. NIH publication n°02-3659. February 2002. NIH publication n°02-3659. January 2005. www.ginasthma.org.
2. British Thoracic Society, Scottish Intercollegiate guidelines Network. Revised edition November 2005;Thorax,1997
3. Canadian Asthma Consensus Report;CMAJ,1999
4. Differences between asthma exacerbations and poor asthma control;Reddel;Lancet,1999
5. Classification of severe asthma exacerbations: a proposal;Picado;Eur. Respir. J.,1996