@article{CMJ_2003__53_3_a4,
     author = {Khan, Moharram A.},
     title = {Commutativity of rings with constraints involving a subset},
     journal = {Czechoslovak Mathematical Journal},
     pages = {545--559},
     publisher = {mathdoc},
     volume = {53},
     number = {3},
     year = {2003},
     mrnumber = {2000052},
     zbl = {1080.16508},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2003__53_3_a4/}
}