%0 Journal Article %A Grabiner, Sandy %T Ranges of Products of Operators %J Canadian journal of mathematics %D 1974 %P 1430-1441 %V 26 %N 6 %U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1974-137-7/ %R 10.4153/CJM-1974-137-7 %F 10_4153_CJM_1974_137_7