@article{10_4153_CJM_1998_021_2,
     author = {Li, Yuanlin},
     title = {The {Hypercentre} and the {n-Centre} of the {Unit} {Group} of an {Integral} {Group} {Ring}},
     journal = {Canadian journal of mathematics},
     pages = {401--411},
     year = {1998},
     volume = {50},
     number = {2},
     doi = {10.4153/CJM-1998-021-2},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1998-021-2/}
}