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2. Exercise tolerance in chronic airway obstruction;Jones;Am Rev Respir Dis,1971
3. Ventilatory muscle strength and endurance training;Leith;J Appl Physiol,1976
4. Ventilatory muscle endurance training in normal subjects and patients with cystic fibrosis;Keens;Am Rev Respir Dis,1977
5. The maximal expiraflow-volume curve normal standards, variability, and effects of age;Knudson;Am Rev Respir Dis,1976