Tiotropium bromide, a new long-acting antimuscarinic bronchodilator: a pharmacodynamic study in patients with chronic obstructive pulmonary disease (COPD). Dutch Study Group
FP Maesen, JJ Smeets, TJ Sledsens, FD Wald, PJ Cornelissen
European Respiratory Journal 1995 8: 1506-1513; DOI: 10.1183/09031936.95.08091506