%0 Journal Article %A Lange, Ridgley %T A purely analytic criterion for a decomposable operator %J Glasgow mathematical journal %D 1980 %P 69-70 %V 21 %N 1 %U http://geodesic.mathdoc.fr/articles/10.1017/S0017089500003992/ %R 10.1017/S0017089500003992 %F 10_1017_S0017089500003992