RT Journal Article SR Electronic T1 CONGENITAL HEART BLOCK JF British Heart Journal JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 90 OP 102 DO 10.1136/hrt.18.1.90 VO 18 IS 1 A1 Maurice Campbell A1 M. G. Thorne YR 1956 UL http://heart.bmj.com/content/18/1/90.abstract AB