Ruffin, Roy,   1938- <br/><br/>
Principles of economics / 
Roy J. Ruffin, Paul R. Gregory. 
 - 3rd ed. 
 - Glenview, Ill. :  Scott, Foresman,  c1988. 
 - xxxi, 918, [42] p. :  ill. (some col.) ;  27 cm.. 
<br/><br/>Includes bibliographies and index. 
<br/><br/><label>ISBN: </label>067318871X 0673188833 (Marco volume) 0673188825 (Micro volume) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Economics.