@article{10_4153_CMB_1975_021_9,
     author = {Wall, Charles R.},
     title = {The {Fifth} {Unitary} {Perfect} {Number}},
     journal = {Canadian mathematical bulletin},
     pages = {115--122},
     year = {1975},
     volume = {18},
     number = {1},
     doi = {10.4153/CMB-1975-021-9},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1975-021-9/}
}