@article{10_4153_CMB_1991_026_2,
     author = {Beattie, M. A. and S.X., Liu and Stewart, P. N.},
     title = {Comparing {Graded} {Versions} of the {Prime} {Radical}},
     journal = {Canadian mathematical bulletin},
     pages = {158--164},
     year = {1991},
     volume = {34},
     number = {2},
     doi = {10.4153/CMB-1991-026-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1991-026-2/}
}