Tahir, M., A. Khattak, and H. Rashid. “Methionine Synthase A2756G Polymorphism Associated With an Increased Risk of Head and Neck Cancer”. International Journal of Scientific Reports, vol. 6, no. 7, June 2020, pp. 237-42, doi:10.18203/issn.2454-2156.IntJSciRep20202537.