CHENG, K. H.; CHIANG, Y. M.; CHING, A. D-module approach to Liouville’s Theorem for difference operators. New Zealand Journal of Mathematics, [S. l.], v. 53, p. 63–79, 2022. DOI: 10.53733/187. Disponível em: https://nzjmath.org/index.php/NZJMATH/article/view/187. Acesso em: 8 dec. 2022.