RT Journal Article SR Electronic T1 Congenital Atresia of Posterior Choanae JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 210 OP 211 DO 10.1136/adc.23.115.210 VO 23 IS 115 A1 D. Walker Ashcroft A1 A. P. Norman YR 1948 UL http://adc.bmj.com/content/23/115/210.abstract AB