1. Executive Summary: Guidelines for the diagnosis and management of asthma,1991
2. Long-term corticosteroid treatment of asthma;Maunsell;BMJ,1968
3. Methotrexate in the treatment of steroid-dependent asthma;Mullarkey;Ann Allergy,1986
4. Other statistical issues in meta-analysis;Petitti,1994
5. Aminophylline treatment in severe, acute asthma: a meta-analysis;Littenberg;JAMA,1988