Magruder, Daniel Summer, and Stefan Bonn. “Root Demotion: Efficient Post-Processing of Layered Graphs to Reduce Dummy Vertices for Hierarchical Graph Drawing”. Journal of Graph Algorithms and Applications 21, no. 6 (October 1, 2017): 1027–1038. Accessed May 1, 2025. https://www.jgaa.info/index.php/jgaa/article/view/paper448.