RT Journal Article SR Electronic T1 Single screening or double screening for study selection in systematic reviews? JF BMJ Evidence-Based Medicine JO BMJ EBM FD BMJ Publishing Group Ltd SP 149 OP 150 DO 10.1136/bmjebm-2019-111269 VO 25 IS 4 A1 Mahtani, Kamal R A1 Heneghan, Carl A1 Aronson, Jeffrey YR 2020 UL http://ebm.bmj.com/content/25/4/149.abstract AB