RT Journal Article SR Electronic T1 Cochrane corner: vitamin K for improved anticoagulation control in patients receiving warfarin JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 1689 OP 1690 DO 10.1136/heartjnl-2014-307133 VO 101 IS 21 A1 Kamal R Mahtani A1 David Nunan A1 Carl Heneghan YR 2015 UL http://heart.bmj.com/content/101/21/1689.abstract AB