Metformin effects on clinical features, endocrine and metabolic profiles, and insulin sensitivity in polycystic ovary syndrome: a randomized, double-blind, placebo-controlled 6-month trial, followed by open, long-term clinical evaluation. - Moghetti,P.; Castello,R.; Negri,C.; Tosi,F.; Perrone,F.; Caputo,M.; Zanolin,E.; Muggeo,M. (J Clin Endocrinol Metab, 2000)