@article{10_1017_S0017089500009812,
     author = {Longobardi, Patrizia and Maj, Mercede and Rhemtulla, Akbar H.},
     title = {Covering a group with isolators of finitely many subgroups},
     journal = {Glasgow mathematical journal},
     pages = {253--259},
     year = {1993},
     volume = {35},
     number = {2},
     doi = {10.1017/S0017089500009812},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500009812/}
}