Ibragimov, M. M., S. J. Tleumuratov, and J. Seypullaev. “Some Geometric Properties of a Strongly Facially Symmetric Space”. Methods of Functional Analysis and Topology 11, no. 3 (September 25, 2005): 234–238. Accessed December 16, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/281.