Покась, Сергей, and Алина Крутоголова. “The Geometry of Riemannian Space of the Second Approximation”. Proceedings of the International Geometry Center 8, no. 3-4 (February 13, 2020): 53-59. Accessed June 28, 2026. https://journals.ontu.edu.ua/index.php/geometry/article/view/1607.