Serum levels of pepsinogen, gastrin and gastric acid secretion before and after proximal vagotomy for the treatment of gastric ulcer - D'albuquerque, Luiz Augusto Carneiro; Gama Rodrigues, Joaquim José; Laudanna, Antônio Atílio; Pinotti, Henrique Walter (Abcd: Arquivos Brasileiros de Cirurgia Digestiva, 1988)