SHAPIRO, B.; TATER, M. Polynomial Solutions of the Heun Equation. Acta Polytechnica, [S. l.], v. 51, n. 4, 2011. DOI: 10.14311/1416. Disponível em: https://ojst.is.cvut.cz/ojs/index.php/ap/article/view/1416.. Acesso em: 12 may. 2025.