Nand, L.; Mahto, S.; Garg, D. K.; Kumar, B. Vitamin B12 Deficiency in Patients of Type 2 Diabetes Mellitus Treated With Metformin: A Cross Section Observational Study from a Tertiary Care Centre in Sub-Himalayan Region of North India. Int J Res Med Sci 2020, 8, 1248-1253.