RT Journal Article SR Electronic T1 Role of oral anticoagulation in management of atrial fibrillation JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 813 OP 817 DO 10.1136/hrt.2003.021642 VO 90 IS 7 A1 Eugene Crystal A1 Stuart J Connolly YR 2004 UL http://heart.bmj.com/content/90/7/813.abstract AB