@article{CMUC_1978_19_3_a1,
     author = {Sullivan, Robert P.},
     title = {Ideals in transformation semigroups},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {431--446},
     year = {1978},
     volume = {19},
     number = {3},
     mrnumber = {508952},
     zbl = {0399.20056},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1978_19_3_a1/}
}