AU - Willoughby, Jr RE TI - BEware observational studies in neonatal practice PT - JOUR DP - 2003 TA - Archives of Pediatrics & Adolescent Medicine pages = {934-935}, VI - 157 IP - 9 AID - 10.1001/archpedi.157.9.934-a [doi] 4100 - http://dx.doi.org/10.1001/archpedi.157.9.934-a SO - Archives of Pediatrics & Adolescent Medicine September 1, 2003 157(9):934