SHAPIRO, B.; TATER, M. Polynomial Solutions of the Heun Equation. Acta Polytechnica, Prague, Czech Republic, v. 51, n. 4, 2011. DOI: 10.14311/1416. Disponível em: https://ojs.cvut.cz/ojs/index.php/ap/article/view/1416. Acesso em: 1 feb. 2025.