Clinical role of CYP2C19 in the management of failed Helicobacter pylori (Hp) infected patients. - Perna, F.; Sapone, A.; Gatta, L.; Trespidi, S.; Paolini, M.; Biagi, G.L.; Forti, G. Cantelli; Osborn, J.; Ricci, C.; Tampieri, A.; Miglioli, M.; Vaira, D. (Gut (0017-5749), 2002)