PIZA VOLIO, Eduardo. Heads reproduction in Hercules and hidras battles. Pro Mathematica, [S. l.], v. 16, n. 31-32, p. 145–164, 2002. Disponível em: https://revistas.pucp.edu.pe/index.php/promathematica/article/view/8189. Acesso em: 24 dic. 2025.