Prochorov, Nikolai P., and Ekaterina N. Dul. “Graphs of Intersections of Closed Polygonal Chains”. Journal of the Belarusian State University. Mathematics and Informatics, no. 1 (April 12, 2021): 54–68. Accessed September 6, 2026. https://journals.bsu.by/index.php/mathematics/article/view/3379.