Saragih, Ita Daryanti, Ira Suarilah, and Ice Septriani Saragih. “Prognosis of Survival Among Older Adults With COVID-19: A Systematic Review and Meta-Analysis”. International journal of health sciences 6, no. S5 (June 23, 2022): 4429–4444. Accessed April 22, 2026. https://www.sciencescholar.us/journal/index.php/ijhs/article/view/9576.