@article{CMJ_2002_52_2_a12,
     author = {Chajda, Ivan and L\"anger, Helmut},
     title = {A note on normal varieties of monounary algebras},
     journal = {Czechoslovak Mathematical Journal},
     pages = {369--373},
     year = {2002},
     volume = {52},
     number = {2},
     mrnumber = {1905444},
     zbl = {1011.08006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2002_52_2_a12/}
}