VOUTSADAKIS, George. Categorical Abstract Algebraic Logic: Closure Operators on Classes of PoFunctors. Armenian Journal of Mathematics, Yerevan, Armenia, v. 4, n. 1, p. 1–24, 2012. Disponível em: https://armjmath.sci.am/index.php/ajm/article/view/81. Acesso em: 3 apr. 2025.