ShuhayloO. “Affine Curvature of Plane Geodesic Lines on Affine Hypersurfaces”. Ukrains’kyi Matematychnyi Zhurnal 69, no. 4 (April 25, 2017): 565-574. Accessed December 3, 2020. http://umj.imath.kiev.ua/index.php/umj/article/view/1716.