Sunthornwat, Rapin, and Sirikanlaya Sookkhee. “Delay Time Parameter and Its Confidence Interval of Predictive Time Series of COVID-19 Outbreak Between the First and the Second Wave”. Journal of Mathematical and Fundamental Sciences 53, no. 2 (October 12, 2021): 306-323. Accessed October 14, 2025. https://journals.itb.ac.id/index.php/jmfs/article/view/16410.