Habib, Asad, et al. “EFFECT OF USING VERSION IMAGE GUIDED SYSTEM ON SURGICALLY INDUCED ASTIGMATISM (SIA) IN PATIENTS UNDERGOING CATARACT SURGERY”. Pakistan Armed Forces Medical Journal, vol. 68, no. 6, Dec. 2018, pp. 1533-37, https://www.pafmj.org/PAFMJ/article/view/2535.