“The Association of Inflammatory markers,Interleukin-6, Procalcitonin, COVID-19 Immunoglobulins With the Severity of COVID-19 Patients”. History of Medicine 9, no. 1 (February 28, 2023). Accessed September 13, 2025. http://www.historymedjournal.com/index.php/medicine/article/view/880.