LEE, KYEONGHO, and Byoung Chun Ha. “The Impact of Customer Engagement on Service Coordination Costs in Content service:: the Mediating Effect of Customer Response Profitability”. International Journal of Social Sciences and Humanities Invention 6, no. 11 (November 20, 2019): 5716–5723. Accessed April 25, 2024. https://valleyinternational.net/index.php/theijsshi/article/view/2414.