00262nam a2200097Ia 4500008004100000082002000041100002100061245004100082260002800123300001300151260227b        |||||||| |||| 00| 0 eng d  a338.06bM287.ET  aMansfield, Edwin  aEconomics of technological changeb/  aLondon:bLongman,c1969  ax, 257p.