000 00314cam a22000977a 4500
008 180718b1962 xxu||||| |||| 00| 0 eng d
082 _aYA6084 Un3r
245 _aThe rate and direction of inventive activity: economic and social factors
260 _aPrinceton
_bPrinceton University Press
_c1962
650 _aInventions
999 _c501663
_d501663