Sharma, P. ., K. . Singh, R. . Bhatnagar, and R. . Jain. “Assessment of Vitamin B12 Deficiency and Associated Factors in Patients Attending Tertiary Care Hospital of Southern Rajasthan”. National Journal of Community Medicine, vol. 9, no. 10, Oct. 2018, pp. 740-4, https://njcmindia.com/index.php/file/article/view/806.