Maryam Nadeem, et al. “Correlation of Vitamin B12 Deficiency With Diabetic Neuropathy in Type II Diabetics on Long-Term Metformin Therapy”. Pakistan Journal of Medical Research, vol. 64, no. 2, July 2025, pp. 68-72, https://www.pjmr.org.pk/index.php/pjmr/article/view/879.