Wolski, Michał, and Andrzej Stasiak. “New Features in UML Syntax and Semantics”. Studia Informatica. System and information technology 7, no. 1-2 (December 15, 2006): 265–276. Accessed October 30, 2024. https://czasopisma.uws.edu.pl/studiainformatica/article/view/2867.