Willoughby, Stephen S.  et, al. <br/><br/>
Real math / 
Stephen S. Willoughby et, al. 
 - Chicago :  Open court,  c1991. 
 - 456 p.:  ill. 
<br/><br/><label>ISBN: </label>0812606353 
<br/><br/><label>Dewey Class. No.: </label>510