A retrospective study of hearing, speech and language function in children with clefts following palatoplasty and veloplasty procedures at 18–24 months of age - Schönweiler, R; Lisson, J A; Schönweiler, B; Eckardt, A; Ptok, M; Tränkmann, J; Hausamen, J E (Int J Pediatr Otorhinolaryngol, 1999)