[1]
“Modeling and design of learning content management systems: UML as a tool for learning system design”, Ann. Sofia Univ. Fac. Math. and Inf., vol. 98, pp. 231–242, Dec. 2008, Accessed: Jan. 11, 2026. [Online]. Available: https://annual.uni-sofia.bg/index.php/fmi/article/view/140