KHAN, Mumtaz Ahmad; SINGH, Mukesh Pal. A study of two variables Legendre polynomials. Pro Mathematica, [S. l.], v. 24, n. 47-48, p. 201–223, 2010. Disponível em: https://revistas.pucp.edu.pe/index.php/promathematica/article/view/10280. Acesso em: 24 dic. 2025.