Endoscopic treatment of Zenker's diverticulum by harmonic scalpel - Hondo, Fábio Yuji; Maluf-Filho, Fauze; Giordano-Nappi, José Humberto; Neves, Carla Zanelatto; Cecconello, Ivan; Sakai, Paulo (Gastrointestinal endoscopy, 2011)