Stichting Mathematisch Centrum
Stichting Mathematisch Centrum. Zuivere Wiskunde

Baayen, P. C., Kuyk, W.& Maurice, M. (1962). On the orbits of the hat-function and on countable maximal commutative semigroups of continuous mappings of the unit interval into itself. In Stichting Mathematisch Centrum. Zuivere Wiskunde (ZW 18/62). Stichting Mathematisch Centrum.