Ardiansyah, Muhammad Yudhi, et al. “The Relationship Between COVID-19 Vaccination and the Severity of COVID-19 in Patients Treated for the Period August 2021 – August 2022 at Arifin Achmad General Hospital, Riau Province, Indonesia”. Bioscientia Medicina : Journal of Biomedicine and Translational Research, vol. 8, no. 3, Dec. 2023, pp. 4111-6, https://doi.org/10.37275/bsm.v8i3.938.