%0 Journal Article %A Abramson, Morton %T Explicit Expressions for a Class of Permutation Problems %J Canadian mathematical bulletin %D 1964 %P 345-350 %V 7 %N 3 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1964-031-5/ %R 10.4153/CMB-1964-031-5 %F 10_4153_CMB_1964_031_5