@article{Safiulina2015graphical,
author={Safiulina, Y.. and Shmurnov, V..},
title={Graphical Proof of the Main Theorem of Non-Euclidean Geometry},
journal={Geometry & Graphics},
publisher={INFRA-M Academic Publishing LLC.},
year={2015},
pages={18-23},
volume={3},
issue={3},
}