Gor’kavyiV. A., DiskantV. I., and MilkaA. D. “International Conference on Geometry "In the Large"”. Ukrains’kyi Matematychnyi Zhurnal 52, no. 7 (July 25, 2000): 1007-1008. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4503.