RT Journal Article SR Electronic T1 Occupation and COPD JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 215 OP 215 DO 10.1136/oem.2004.017426 VO 62 IS 4 A1 D C Christiani YR 2005 UL http://oem.bmj.com/content/62/4/215.abstract AB