Willoughby, Stephen S. <br/><br/>
Real math / 
Stephen S Willoughby. 
 - La Salle :  Open court,  c1987. 
 - 436 p. 
<br/><br/><label>ISBN: </label>0812605071 
<br/><br/><label>LC Class. No.: </label>QA107  / .R43