Aldi Eka Wahyu Widianto, et al. “Penentuan Effective Reproduction Number COVID-19 Dengan Metode Particle Swarm Optimization Pada Enam Provinsi Di Pulau Jawa”. Limits: Journal of Mathematics and Its Applications, vol. 20, no. 2, July 2023, pp. 131-43, https://journal.its.ac.id/index.php/limits/article/view/5507.