03.01.2002
Inhaled formoterol dry powder versus ipratropium bromide in chronic obstructive pulmonary disease
R. Dahl, L.A.P.M. Greefhorst, D. Nowak, V. Nonikov, A.M. Byrne, M.H. Thompson, D. Till, G. della Cioppa, on behalf of the Formoterol in Chronic Obstructive Pulmonary Disease I (FICOPD I) Study Group
American Journal of Respiratory and Critical Care Medicine, 2001; 164: 778-784