1. Kombinatorik, II;Aigner,1976
2. O čisle monotonnych k-značnych funkcij;Alekseev;Problemy Kibernet.,1974
3. K. Engel, Optimal representations of partially ordered sets and a limit Sperner theorem, submitted.
4. Potoki v setjach;Ford,1966
5. The structure of Sperner k-families;Greene;J. Combin. Theory Ser. A,1976