00327nam a2200109Ia 4500082002100000100004300021245005000064260004300114300002200157500000500179700003300184  a338.901bG878.IG  aGrossman, Gene M. and Helpman, Elhanan  aInnovation and growth in the global economyb  aCambridgebMIT Pressc1991 (Rep. 1992)  axiv, 359p. Index,  a  aHelpman, Elhanan ; jt. auth.