Tobing, T. C. L., T. Ontoseno, S. Rahayuningsih, R. A. Ganie, and Y. Siregar. “Relationship Between Environmental Factors and Rheumatic Heart Disease”. Open Access Macedonian Journal of Medical Sciences, vol. 9, no. B, Dec. 2021, pp. 1795-8, doi:10.3889/oamjms.2021.7836.