organized by the Wiskundig Genootschap of the Netherlands on November 7, 1973, in honour of J. de Groot (1914-1972) ; P. C. Baayen (ed.)

Mathematisch Centrum 1974 Mathematical Centre tracts 52

Available at 15 libraries

[editorial committee, Johan C.H. Gerretsen, Johannes de Groot]

Noordhoff , North-Holland Pub. 1954-1957

v. 1 , v. 2 , v. 3

Available at 24 libraries

door J. de Groot

Van Gorcum 1942 Getal en figuur : Van Gorcum's wiskundige reeks 2

Available at 1 libraries