Stichting Mathematisch Centrum
Stichting Mathematisch Centrum. Zuivere Wiskunde

Paalman-de Miranda, A. B. (1967). Topological representation of semigroups : (general topology and its applications to modern analysis and algebra, 2. prague 1966, p 276-282). Stichting Mathematisch Centrum. Zuivere Wiskunde. Stichting Mathematisch Centrum.