@article{CMJ_2008__58_2_a11,
     author = {Jakub{\'\i}kov\'a-Studenovsk\'a, Danica and P\'ocs, Jozef},
     title = {Cardinality of retracts of monounary algebras},
     journal = {Czechoslovak Mathematical Journal},
     pages = {469--479},
     publisher = {mathdoc},
     volume = {58},
     number = {2},
     year = {2008},
     mrnumber = {2411102},
     zbl = {1174.08303},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2008__58_2_a11/}
}