The pharyngeal flap surgery in patients with velopharyngeal insufficiency: perceptual and nasometric speech assessment - Zuiani, Tarsis Benencase Botelho; Trindade, Inge Elly Kiemle; Yamashita, Renata Paciello; Trindade Junior, Alceu Sergio (The Brazilian Journal of Dysmorphology and Speech-Hearing Disorders, 1998)