Ruffin, Roy J. <br/><br/>
Principles of economics / 
Roy J. Ruffin, Paul R. Gregory. 
 - 5th ed. 
 -  Harper Collins  1993. 
<br/><br/>3452 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Economics.
<br/><br/><label>LC Class. No.: </label>HB171.5  / Ruf.