@article{10_4153_CMB_1993_020_x,
     author = {Costa, Antone},
     title = {A {Sequence} of {Results} on {Class} {Number} {Congruences}},
     journal = {Canadian mathematical bulletin},
     pages = {139--143},
     year = {1993},
     volume = {36},
     number = {2},
     doi = {10.4153/CMB-1993-020-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1993-020-x/}
}