1. and , Graph Theory with Applications, Macmillan, London and Elsevier, New York (1976).
2. Electronic computation of squared rectangles. Thesis, Technische Hogeschool Eindhoven, The Netherlands (1962);
3. also in Philips Res. Rep. 17 (1962) 523–612.
4. Algorithmic calculation of the order of the automorphism group of a graph. Memorandum No. 221, Faculty of Applied Mathematics, University of Twente, Enschede, The Netherlands (1978).