A Recursive Formula and an Estimation for a Specific Exponential Sum. Communications in Mathematical Research, [S. l.], v. 38, n. 2, p. 184–205, 2022. DOI: 10.4208/cmr.2021-0030. Disponível em: https://global-sci.com/index.php/cmr/article/view/9073. Acesso em: 5 dec. 2025.