@article{10_4153_CMB_1974_107_7,
     author = {Mura, Roberta Botto},
     title = {Radical {Classes} need not have a {Unique} {Maximal} {R} {0-Closed} {Subclass}},
     journal = {Canadian mathematical bulletin},
     pages = {597--598},
     year = {1974},
     volume = {17},
     number = {4},
     doi = {10.4153/CMB-1974-107-7},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1974-107-7/}
}