Endoscopic mucosal resection for early gastric cancer: comparison of two modifications of the cap method - Kume, K; Yamasaki, M; Tashiro, M; Santo, N; Syukuwa, K; Maekawa, S; Aritome, G; Matsuoka, H; Murase, T; Yoshikawa, I; Otsuki, M (Endoscopy, 2008)