Stichting Mathematisch Centrum
Stichting Mathematisch Centrum. Zuivere Wiskunde

de Groot, J., Strecker, G. E., & Wattel, E. (1967). The compactness operator in general topology : (general topology and its relations to modern analysis and algebra, 2. prague 1966, p 161-163). Stichting Mathematisch Centrum. Zuivere Wiskunde. Stichting Mathematisch Centrum.