RT Journal Article SR Electronic T1 Interactions with hormonal contraception JF British Journal of Family Planning JO Br J Fam Plann FD BMJ Group SP 109 OP 111 DO 10.1783/147118900101194193 VO 26 IS 2 A1 Alyson Elliman YR 2000 UL http://jfprhc.bmj.com/content/26/2/109.abstract AB