On Lie’s Reduction Theorem with an Application to Isentropic Fluid Spheres. Al-Nahrain Journal of Science, [S. l.], v. 9, n. 1, p. 80–84, 2006. Disponível em: https://anjs.edu.iq/index.php/anjs/article/view/1699. Acesso em: 18 apr. 2025.