A. Sicras-Mainar and R. Navarro-Artieda, “Combination therapy of metformin vs dipeptidulpeptidase inhibitors and sulfonylureas in type 2 diabetes: clinical and economic impact”, Rev Peru Med Exp Salud Publica, vol. 31, no. 4, Dec. 2014, doi: 10.17843/rpmesp.2014.314.111.