@article{10_21136_CMJ_1977_101485,
     author = {Schwarz, \v{S}tefan},
     title = {A counting theorem in the semigroup of circulant {Boolean} matrices},
     journal = {Czechoslovak Mathematical Journal},
     pages = {504--510},
     publisher = {mathdoc},
     volume = {27},
     number = {3},
     year = {1977},
     doi = {10.21136/CMJ.1977.101485},
     mrnumber = {0457603},
     zbl = {0382.15010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1977.101485/}
}