4Light RW,Muro JR,Sato RI,et al. Effects of oral morphine on breathlessness and exercise tolerance in patients with chronic ob structive pulmonary disease. Am Rev Respir Dis. 1989,139 ( 1 ) : 126~133
5George CF,Bayliff CD Management of insomnia in patients with chronic obstructive pulmonary disease. Drugs. 2003,63(4 ): 379~387