Beknazaryan, A.F. “TOPOLOGIES ON THE GENERALIZED PLANE”. Proceedings of the YSU A: Physical and Mathematical Sciences 48, no. 3 (235) (November 3, 2014): 8–12. Accessed May 19, 2024. https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol48_no3_2014_pp008-012.