FEDCHENKO, Yu. S. Normal and tangential geodesic deformations of the surfaces of revolution. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 61, n. 10, p. 1396–1402, 2009. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3109. Acesso em: 14 apr. 2025.