AUINGER, Karl. A CLASS OF INVERSE SEMIGROUPS WITH BOOLEAN CONGRUENCE LATTICES Periodica Polytechnica Transportation Engineering, [S. l.], v. 19, n. 1-2, p. 3–13, 1991. Disponível em: https://pp.bme.hu/tr/article/view/6676. Acesso em: 13 apr. 2025.