Ryan, Thomas Arthur. <br/><br/>
Work and effort :   the psychology of production 

 - New York :   The Ronald Press Company,   1947. 
 - 323 p. ; 23 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>PSICOLOGIA<br/>TRABAJO
<br/><br/><label>Universal Decimal Class. No.: </label>658:15