@article{CMUC_1974_15_2_a3,
     author = {Kepka, Tom\'a\v{s}},
     title = {Costable rings},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {245--257},
     year = {1974},
     volume = {15},
     number = {2},
     mrnumber = {0349756},
     zbl = {0287.16019},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1974_15_2_a3/}
}