Ruffin, Roy  1938- <br/><br/>
Principles of economics 
Roy J. Ruffin, paul R. Gregory. 
 - 6th. ed. 
 - Reading, Massachusetts  Addison Wesley  1997 
 - xxxi, 706p.  ill.  26cm. 
<br/><br/> Include index 
<br/><br/><label>ISBN: </label>0673994880 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Economics.