Agakhanova, Yana, Aleksander Nikachev, and Irina Oblasova. “On Codimension 3 Singular Points of First-Order Implicit Differential Equations”. Advances in Systems Science and Applications 23, no. 1 (April 16, 2023): 8-21. Accessed July 20, 2024. https://ijassa.ipu.ru/index.php/ijassa/article/view/1382.