VELÁSQUEZ LÓPEZ, Roberto. Federico Villareal y Villareal. Pro Mathematica, [S. l.], v. 14, n. 27-28, p. 135–154, 2000. Disponível em: https://revistas.pucp.edu.pe/index.php/promathematica/article/view/8163. Acesso em: 12 dic. 2025.