Über die Realisierung von Boole-Algebren als Boole-Algebren regulär offener Mengen. (German) [On the realization of Boole algebras as Boole algebras of regular open sets]. In: General Topology and its Relations to Modern Analysis and Algebra. Proceedings of the second Prague topological symposium, 1966. Academia Publishing House of the Czechoslovak Academy of Sciences, Praha, 1967. pp. 133-139