Осіпчук, Тетяна, and Максим Ткачук. “On Weakly 1-Convex Sets in the Plane”. Proceedings of the International Geometry Center 16, no. 1 (May 4, 2023): 42-49. Accessed August 11, 2026. https://journals.ontu.edu.ua/index.php/geometry/article/view/2440.