Tangent codes. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics, [S. l.], v. 111, p. 91–114, 2024. DOI: 10.60063/gsu.fmi.111.91-114. Disponível em: https://annual.uni-sofia.bg/index.php/fmi/article/view/989. Acesso em: 16 dec. 2025.