Alam, Muhammad Jawaherul, Md. Abul Hassan Samee, Mashfiqui Rabbi, and Md. Saidur Rahman. “Minimum-Layer Upward Drawings of Trees”. Journal of Graph Algorithms and Applications 14, no. 2 (January 1, 2010): 245–267. Accessed June 30, 2024. https://jgaa.info/index.php/jgaa/article/view/paper206.