Kitagawa, G. “COMBINING DATA ASSIMILATION AND THE SIR INFECTION EQUATION FOR BETTER UNDERSTANDING OF COVID-19 ”. International Journal of Interdisciplinary Research in Statistics, Mathematics and Engineering (IJIRSME), vol. 9, no. 2, Aug. 2023, pp. 34-48, https://sadijournals.org/index.php/IJIRSME/article/view/172.