RT Journal Article SR Electronic T1 Pediatric echocardiography JF British Heart Journal JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 589 OP 589 DO 10.1136/hrt.70.6.589-a VO 70 IS 6 A1 Webber, S YR 1993 UL http://heart.bmj.com/content/70/6/589.2.abstract AB