TIWARI, K. The Universal Complex over an Algebra. The Journal of the Indian Mathematical Society, [S. l.], v. 31, n. 1, p. 11–22, 1967. DOI: 10.18311/jims/1967/16786. Disponível em: http://informaticsjournals.com/index.php/jims/article/view/16786. Acesso em: 4 may. 2024.