Abd Elkhalik, Sahar Mahmood, and Barween Alkurdi. “Consumer Management of Digital Subscription Portfolios: A Systematic Literature Review”. International Journal of Management and Marketing Intelligence 3, no. 2 (June 30, 2026): 11–32. Accessed September 25, 2026. https://www.ijmmi.org/index.php/ijmmi/article/view/140.