A. Al-Hamdi, M. Al-Gahhafi, S. Al-Roshdi, S. Jaju, A. Al-Mamari, and A. M. Al Mahrezi, “Vitamin B12 Deficiency in Diabetic Patients on Metformin Therapy: A cross-sectional study from Oman”, Sultan Qaboos Univ Med J, vol. 20, no. 1, pp. e90–94, Mar. 2020.