BAL, Zeynep, and Eylem DENİZ. “AN APPLICATION OF DATA ENVELOPMENT ANALYSIS TO DIGITAL MARKETING SECTOR”. Eurasian Eononometrics, Statistics and Emprical Economics Journal, no. 17 (September 15, 2020): 99–106. Accessed November 11, 2026. https://eurasianacademy.org/index.php/econstat/article/view/1015.