@article{CMJ_2007__57_3_a14,
     author = {Jakub{\'\i}kov\'a-Studenovsk\'a, Danica and P\'ocs, Jozef},
     title = {Test elements and the {Retract} {Theorem} for monounary algebras},
     journal = {Czechoslovak Mathematical Journal},
     pages = {975--986},
     publisher = {mathdoc},
     volume = {57},
     number = {3},
     year = {2007},
     mrnumber = {2356934},
     zbl = {1174.08302},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2007__57_3_a14/}
}