@article{10_1007_s10587_011_0066_2,
     author = {Brualdi, Richard A. and Kiernan, Kathleen P.},
     title = {Hall exponents of matrices, tournaments  and their line digraphs},
     journal = {Czechoslovak Mathematical Journal},
     pages = {461--481},
     publisher = {mathdoc},
     volume = {61},
     number = {2},
     year = {2011},
     doi = {10.1007/s10587-011-0066-2},
     mrnumber = {2905416},
     zbl = {1249.15008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.1007/s10587-011-0066-2/}
}