RT Journal Article SR Electronic T1 Betel quid seller syndrome JF Occupational and Environmental Medicine JO Occup Environ Med FD BMJ Publishing Group Ltd SP 144 OP 144 DO 10.1136/oem.2009.049809 VO 67 IS 2 A1 G Dwivedi A1 S Dwivedi YR 2010 UL http://oem.bmj.com/content/67/2/144.abstract AB