1. B. A. Rosenfeld and M. P. Zamakhovsky, Geometry of Lie groups. Symmetric, Parabolic and Periodic Spaces [in Russian], Moscow Center for Continuous Mathematical Education, Moscow (2003).
2. B. A. Rosenfeld, Non-Euclidean spaces [in Russian], Nauka, Moscow (1969).
3. L. N. Romakina, Geometry of the Hyperbolic Plane of Positive Curvature. Part 1: Trigonometry [in Russian], Saratov University, Saratov (2013).
4. L. N. Romakina, Geometry of the Hyperbolic Plane of Positive Curvature. Part 2: Transformations and Simple Partitions [in Russian], Saratov University, Saratov (2013).
5. N. V. Efimov, Higher Geometry [in Russian], Mir, Moscow (1980).