Purchase, Helen, Jo-Anne Allder, and David Carrington. “Graph Layout Aesthetics in UML Diagrams: User Preferences”. Journal of Graph Algorithms and Applications 6, no. 3 (January 1, 2002): 255–279. Accessed December 7, 2025. https://jgaa-v5.cs.brown.edu/index.php/jgaa/article/view/paper54.