Sumner, William Graham,  1840-1910 <br/><br/>
What social classes owe to each other / 
By William Graham Sumner. 
 - New Haven :  Yale University Press,  [1925]. 
 - 169 p. ;  18 c. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Social ethics<br/>Economics<br/>Social clases