@article{10_1017_S0017089500009733,
     author = {Brodie, Marc A. and Kappe, Luise-Charlotte},
     title = {Finite coverings by subgroups with a given property},
     journal = {Glasgow mathematical journal},
     pages = {179--188},
     year = {1993},
     volume = {35},
     number = {2},
     doi = {10.1017/S0017089500009733},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500009733/}
}