- Highly effective second-line anti-Helicobacter pylori therapy in patients with previously failed metronidazole-based therapy. Lerang, F., Moum, B., Haug, J.B., Berge, T., Tolås, P., Sandvei, P.K., Torp, R., Tønnesen, T. Scand. J. Gastroenterol. (1997)