00773nam0-22002531i-450-990002676990403321000267699FED01000267699(Aleph)000267699FED0100026769920000920d1967----km-y0itay50------baENGProductivity differences within the servicesector.de Fuchs V. e Wilburn J.New YorkNational Bureau of Economic Research1967Fuchs,Victor R.<1924- >46998Wilburn,Jean AlexanderITUNINARICAUNIMARCBK99000267699040332112-7-11s.i.ECAECAProductivity differences within the servicesector428257UNINAING01