RT Journal Article SR Electronic T1 Risk of venous thromboembolism in oral contraceptive users varies according to progestin type JF Evidence Based Nursing JO Evid Based Nurs FD BMJ Publishing Group Ltd and RCN Publishing Company Ltd SP 82 OP 83 DO 10.1136/ebnurs-2011-100480 VO 15 IS 3 A1 Susan S Jick YR 2012 UL http://ebn.bmj.com/content/15/3/82.abstract AB