ZHANG, Li Juan; XIN, Xiao Long. Derivations and differential filters on semihoops . Italian Journal of Pure and Applied Mathematics, [S. l.], v. 42, p. 916–933, 2019. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/7165. Acesso em: 27 oct. 2026.