Widjanarko, M., M. Nindya, G. Fernandez, and A. Jovito. “Comorbidities and COVID-19 Severity in Pediatric Patients: Systematic Review and Meta-Analysis”. Paediatrica Indonesiana, Vol. 62, no. 1, Feb. 2022, pp. 51-60, doi:10.14238/pi62.1.2022.51-60.