Somnath Maitra, Kaushik Hazra, Sekhar Chakraborty, Biswaroop Mukherjee, and Sunetra Roy. “Variable Presentations of Vitamin B12 Deficiency in Eastern India: A Case Series”. International Journal of Health and Clinical Research, vol. 5, no. 1, Jan. 2022, pp. 548-51, https://www.ijhcr.com/index.php/ijhcr/article/view/4658.