RT Journal Article SR Electronic T1 THE WORLD-WIDE DISTRIBUTION OF TRACHOMA JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 513 OP 541 DO 10.1136/bjo.22.9.513 VO 22 IS 9 A1 A. F. MacCallan YR 1938 UL http://bjo.bmj.com/content/22/9/513.abstract AB