@article{10_21136_CMJ_1989_102300,
     author = {Magill, Kenneth D., Jr.},
     title = {On the ideals of the semigroup of the 1-sphere},
     journal = {Czechoslovak Mathematical Journal},
     pages = {248--261},
     publisher = {mathdoc},
     volume = {39},
     number = {2},
     year = {1989},
     doi = {10.21136/CMJ.1989.102300},
     mrnumber = {992132},
     zbl = {0684.20056},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1989.102300/}
}