PT - JOURNAL ARTICLE AU - Crompton, G K TI - Effectiveness of four different inhalers in COPD. AID - 10.1136/thx.51.4.454 DP - 1996 Apr 01 TA - Thorax PG - 454--454 VI - 51 IP - 4 4099 - http://thorax.bmj.com/content/51/4/454.1.short 4100 - http://thorax.bmj.com/content/51/4/454.1.full SO - Thorax1996 Apr 01; 51