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). In Stichting Mathematisch Centrum. Zuivere Wiskunde (ZW 11/67/R). Stichting Mathematisch Centrum.