1. Adámek, J., Herrlich, H., Strecker, G.E.: Abstract and Concrete Categories. John Wiley & Sons, New York (1990)
2. Császár, Á.: Foundations of General Topology. Pergamon Press, Oxford (1963)
3. Dowker, C.H., Papert Strauss, D.: Separation axioms for frames. Colloquia Mathematica Societatis János Bolyai 8, 223–240 (1974). (Topics in Topology Keszthely (Hungary) 1972)
4. Engelking, R.: General Topology. Polish Sci. Publ., Warszawa (1977)
5. Gierz, G. Hofmann, K.H., Keimel, K., Lawson, J.D., Mislowe, M., Scott, D.S.: A Compendium of Continuous Lattices. Springer-Verlag, Berlin (1980)