KRISHNAN, V. S. Theory of Demi-Group Structures, II: Uniform Demi Groups and Duality. The Journal of the Indian Mathematical Society, [S. l.], v. 24, n. 1-2, p. 283–318, 1960. DOI: 10.18311/jims/1960/16914. Disponível em: https://www.informaticsjournals.com/index.php/jims/article/view/16914. Acesso em: 5 may. 2024.