1. Decompositions of sets and spaces, I, II, III;Dekker;Indag. Math.,1956
2. Decompositions of sets and spaces, I, II, III;Dekker;Indag. Math.,1957
3. Orthogonal isomorphic representations of free groups;Groot;Can. J. Math.,1956
4. On the decomposition of Euclidean spaces;Mycielski;Bull. Ac. Pol. Sci.,1956
5. On the congruence of sets;Mycielski;Bull. Ac. Pol. Sci.,1956