Ruffin,Roy J <br/><br/>
Principles of economics 
/ by Roy J. Ruffin and Paul R. Gregory  
 - 4th ed. 
 - London:   Foresman and Company,   1990. 
 - xxxii,851p. 
<br/><br/><label>ISBN: </label>9780673460202 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Economics <br/>Elasticity<br/>Monopoly<br/>World Economics 
<br/><br/><label>Dewey Class. No.: </label>330  / RUF/P