Gray, H. Peter. <br/><br/>
Generalized Theory of International Trade /  

 - 1st ed /  
 - London :   Macmillan Press Ltd.. 
 - p201 :  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Economics 
<br/><br/><label>Dewey Class. No.: </label>X:5.1  / L6