Ahmad, A., H. U. Rehman, Ihtisham, T. Rasheed, A. Khan, and S. Malak. “Early Detection of ENT Symptoms in Mild to Moderate COVID-19 Cases: A Case Control Study”. Pakistan Journal of Chest Medicine, vol. 29, no. 2, June 2023, pp. 230-6, https://www.pjcm.net/index.php/pjcm/article/view/900.