1. Anderson parison of oxitropium bromide and ipratropium bromide in asthma;Peel;Eur J Respir Dis
2. Definition and classificaton of chronic bronchitis for clinical and epidemiological purposes;Council, Medical Research;Lancet,1965
3. Peak expiratory flow in normal subjects;Gregg, I.; Nunn, A.J.;Br Med J,1973
4. Multiple range, multiple F-test;Duncan, D.B.;Biometric,1952