Hasan, S. H., R. Samad, J. C. Das, F. Ara, and M. A. Faisal. “Hyperpigmentation With Vitamin B12 Deficiency in an Adolescent Girl”. Journal of Bangladesh College of Physicians and Surgeons, vol. 39, no. 1, Nov. 2020, pp. 62-67, doi:10.3329/jbcps.v39i1.50461.