Taner, Mehmet Tolga, Ibrahim Sahbaz, Gamze Kagan, Kamal Atwat, and Engin Erbas. 2013. “Development of Six Sigma Infrastructure for Strabismus Surgeries”. International Review of Management and Marketing 4 (1):49-58. https://econjournals.com./index.php/irmm/article/view/672.