Arayawudhikul, N., B. Sakboon, J. Cheewinmetasiri, A. Chartirungsun, B. Sripisuttrakul, and R. Muenpa. “Preliminary Report of Off-Pump Coronary Artery Bypass Grafting (OPCABG) at Lampang Hospital”. The Thai Journal of Surgery, vol. 35, no. 1, Mar. 2014, pp. 6-10, https://he02.tci-thaijo.org/index.php/ThaiJSurg/article/view/227733.