Research Article
Prevalence of asthma and COPD in general practice in 1992: has it changed since 1977?
P R Tirimanna, C P van Schayck, J J den Otter, C van Weel, C L van Herwaarden, G van den Boom, P M van Grunsven and W J van den Bosch
British Journal of General Practice 1996; 46 (406): 277-281.