RT Journal Article SR Electronic T1 Drug resistant tuberculosis: problems on the horizon. JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 957 OP 958 DO 10.1136/thx.48.10.957 VO 48 IS 10 A1 Ormerod, L P YR 1993 UL http://thorax.bmj.com/content/48/10/957.abstract AB