%0 Journal Article %A Putnam, C. R. %T On Differences of Unitarily Equivalent Self-Adjoint Operators† %J Glasgow mathematical journal %D 1960 %P 103-107 %V 4 %N 3 %U http://geodesic.mathdoc.fr/articles/10.1017/S2040618500033992/ %R 10.1017/S2040618500033992 %F 10_1017_S2040618500033992