On functions having periodic orbits which are not potentially minimal

SNOHA, Ľubomír. On functions having periodic orbits which are not potentially minimal. In Ergodic Theory and Related Topics II, GDR, April 20-25, 1986 : proceedings of the Conference, Georgenthal (Thuringia), GDR, April 20 - 25, 1986. - Leipzig : Teubner, 1987. ISBN 3-322-00434-1. ISSN 0138-502X, s. 185-189.