Singh, A., C. M. Kohli, and P. Gupta. “Optic Nerve Sheath Diameter in Glaucoma Patients and Its Correlation With Intraocular Pressure”. International Journal of Health and Clinical Research, vol. 4, no. 2, Jan. 2021, pp. 11-15, https://ijhcr.com/index.php/ijhcr/article/view/771.