H. H. Phan, V. Punyawattananon, D. M. Tri, N. Chotprasert, and K. Sipiyaruk, “Lightweight Opened Hollow Bulb Obturator Using a Precise Positioning Method of Metal Framework in Patients with Partial Maxillectomy: a Case Report: A clinical report”, Khon Kaen Dent J, vol. 22, no. 2, pp. 166–171, Dec. 2019.