TY - JOUR AU - Stampfli, J. G. TI - A Spectral Theory for Duality Systems of Operators on a Banach Space JO - Canadian journal of mathematics PY - 1970 SP - 994 EP - 996 VL - 22 IS - 5 UR - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1970-113-8/ DO - 10.4153/CJM-1970-113-8 ID - 10_4153_CJM_1970_113_8 ER -