RT Journal Article SR Electronic T1 WILLIAM FREEMAN SNOW JF The British Journal of Venereal Diseases JO Br J Vener Dis FD BMJ Publishing Group Ltd SP 189 OP 190 DO 10.1136/sti.26.4.189 VO 26 IS 4 A1 L. W. H., YR 1950 UL http://sti.bmj.com/content/26/4/189.abstract AB