Pioglitazone hydrochloride in combination with metformin in the treatment of type 2 diabetes mellitus: a randomized, placebo-controlled study. - Einhorn,D.; Rendell,M.; Rosenzweig,J.; Egan,J.W.; Mathisen,A.L.; Schneider,R.L, on behalf of the Pioglitazone 027 Study Groups. (Clin Ther, 2000)