@article{10_4153_CMB_1966_018_4,
     author = {Subbarao, M.V. and Warren, L. J.},
     title = {Unitary {Perfect} {Numbers}},
     journal = {Canadian mathematical bulletin},
     pages = {147--153},
     year = {1966},
     volume = {9},
     number = {2},
     doi = {10.4153/CMB-1966-018-4},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1966-018-4/}
}