%0 Journal Article %A Usher, A. O. %T Plethysm of S-Functions %J Canadian journal of mathematics %D 1976 %P 440-445 %V 28 %N 2 %U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1976-044-7/ %R 10.4153/CJM-1976-044-7 %F 10_4153_CJM_1976_044_7