Arif, Saatea, et al. “EFFECT OF SMOKING ON HOMOCYSTEINE, VITAMIN B12 AND FOLIC ACID LEVLES IN THE PATIENTS OF ACUTE MYOCARDIAL INFARCTION”. Journal of Medical Sciences, vol. 18, no. 3, Aug. 2010, pp. 143-6, https://jmedsci.com/Jmedsci/article/view/436.