@article{10_4153_CJM_1970_049_0,
     author = {Biggs, R. G.},
     title = {A {New} {Bound} for {Nil} {U-Rings}},
     journal = {Canadian journal of mathematics},
     pages = {403--407},
     year = {1970},
     volume = {22},
     number = {2},
     doi = {10.4153/CJM-1970-049-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1970-049-0/}
}