Kaidar, E. K., A. K. Turgambayeva, B. S. Zhussupov, B. S. Serik, and M. K. Zhanaliyeva. 2022. “Secondary Attack Rate of the COVID-19: General Characteristics of Confirmed and Probable Cases”. International Journal of Health Sciences 6 (3):1468-82. https://doi.org/10.53730/ijhs.v6n3.13082.