00723nam a2200157Ia 4500008004100000010001200041040001700053082002500070110012100095245011200216260004900328300001300377440007100390500006700461650003700528190328s9999||||xx |||||||||||||| ||und||  a62-7044  aNITILcNITIL  221sta338.018bN277R  aNational Bureau of Economic Research (New York)and Social Science Research Council (US).Committee on Economic Growth 4aThe Rate and direction of inventive activitybeconomic and social factors; a conference of the universities  aPrincetonbPrinceton Univesrsity Pressc1962  ax, 635p.  aNational bureau of economic research.Special conference seri es;13  aA report of the National Bureau of Economic Research, New York  aInventions; Economic development