Chotikavanich, S., P. Kosrirukvongs, J. Duangpatra, P. Prabhasawat, W. Booranapong, C. Chirapapaisan, and S. Srivannaboon. “A Two-Year Outcome of Intrastromal Corneal Ring Segment Implantation in Keratoconus: Initial Report in Thai Patients”. Siriraj Medical Journal, vol. 71, no. 4, July 2019, pp. 302-9, https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/205222.