RT Journal Article SR Electronic T1 Professor Axel Perdrup JF Genitourinary Medicine JO Genitourin Med FD BMJ Publishing Group Ltd SP 172 OP 172 DO 10.1136/sti.67.2.172 VO 67 IS 2 A1 Guthe, Thorstein A1 Waugh, Michael YR 1991 UL http://sti.bmj.com/content/67/2/172.abstract AB