MANUKIAN, S. N. . On Transitive Closures of Two-dimensional Strongly Positive Arithmetical Sets. Mathematical Problems of Computer Science, [S. l.], v. 45, p. 67–76, 2021. Disponível em: http://93.187.165.2/index.php/mpcs/article/view/169. Acesso em: 16 nov. 2024.