@article{10_4153_CMB_1977_025_9,
     author = {Williams, H. C.},
     title = {On {Numbers} {Analogous} to the {Carmichael} {Numbers}},
     journal = {Canadian mathematical bulletin},
     pages = {133--143},
     year = {1977},
     volume = {20},
     number = {1},
     doi = {10.4153/CMB-1977-025-9},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1977-025-9/}
}