Rizal, D. M., and R. A. . Wibowo. “Changes in Physical Activity Among University Students in Indonesia from Before to During the COVID-19 Pandemic: A Retrospective Cohort Study”. Journal of Population and Social Studies [JPSS], vol. 30, Nov. 2021, pp. 128-46, https://so03.tci-thaijo.org/index.php/jpss/article/view/256641.