@article{CMJ_2001__51_3_a2,
     author = {Zhang, Y. and Wang, Y.},
     title = {Uniquely covered radical classes of $\ell$-groups},
     journal = {Czechoslovak Mathematical Journal},
     pages = {473--476},
     publisher = {mathdoc},
     volume = {51},
     number = {3},
     year = {2001},
     mrnumber = {1851541},
     zbl = {1079.06506},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2001__51_3_a2/}
}