Sari, E., T. Tokat, A. Aliyeva, M. Karadag, F. Eren, T. Catli, and L. Olgun. “Assessment of Vitamin D Levels in Patients With Sudden Sensorineural Hearing Loss”. Annals of Medical Research, vol. 30, no. 5, May 2023, pp. 538-44, http://annalsmedres.org/index.php/aomr/article/view/4422.