The Rate and direction of inventive activity :   economic and social factors . 

 - Princeton :      University Press ,  1962 
 - x, 635p. ;  23 cm. 
<br/><br/>Includes bibliographical references and index. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Economic theory
<br/><br/><label>Dewey Class. No.: </label>330.1  / NBER