Argyriou, Evmorfia, Michael Bekos, Michael Kaufmann, and Antonios Symvonis. “On Metro-Line Crossing Minimization”. Journal of Graph Algorithms and Applications 14, no. 1 (January 1, 2010): 75–96. Accessed December 26, 2024. https://jgaa.info/index.php/jgaa/article/view/paper199.