RT Journal Article SR Electronic T1 Farming and asthma JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 211 OP 212 DO 10.1136/oem.2004.019109 VO 62 IS 4 A1 Schenker, M B YR 2005 UL http://oem.bmj.com/content/62/4/211.1.abstract AB