Osipchuk Т. М. 2021. “Topological and Geometric Properties of the Set of 1-Nonconvexity Points of a Weakly 1-Convex Set in the Plane”. Ukrains’kyi Matematychnyi Zhurnal 73 (12), 1657 -72. https://doi.org/10.37863/umzh.v73i12.6890.