Lewis, W. Arthur. <br/><br/>
The Principles of Economic Planning /  

 - Eighth Impression 19 /  
 - London W.C.1 :   George Allen & Unwin Ltd.. 
 - p.128 :  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Economics 
<br/><br/><label>Dewey Class. No.: </label>X:75  / J2;2