Fragmentation of bile duct stones: a prospective systematic in vitro evaluation of argon plasma coagulation, cryotechnology, and water-jet technology - Eickhoff, A.; Koberstein, S.; Rothsching, M.; Gemmel, C.; Eickhoff, J. C.; Riemann, J. F.; Enderle, M. D. (Endoscopy, 2009)