[1] M. Novotný: O jednom problému z teorie zobrazení (Sur un problème de la théorie des applications). Publ. Fac. Sci. Univ. Masaryk Brno (1953), no. 344, 53–64.
[2] M. Novotný:
On some correspondences between relational structures and algebras. Czechoslovak Math. J. 43 (118) (1993), 643–647.
MR 1258426
[3] M. Novotný:
Construction of all homomorphisms of groupoids. Accepted to Czechoslovak Math. J.
MR 1371696