Successful endoscopic lithotripsy using a new digital cholangioscope through an overtube placed by an enteroscope - Hakuta, Ryunosuke; Kogure, Hirofumi; Nakai, Yousuke; Yamada, Atsuo; Takahara, Naminatsu; Mizuno, Suguru; Koike, Kazuhiko (Endoscopy, 2018)