Grolier academic encyclopedia. 

 - USA :   Grolier International,  c 1987. 
 - Vols. :  ill. ;  26 cm. 
<br/><br/>Includes bibliography in every chapter. 
<br/><br/>V. 20- (W-X-Y-Z) ; 
<br/><br/>333  333 
<br/><br/><label>ISBN: </label>0-7172-2017-6 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Encyclopedia.
<br/><br/><label>Dewey Class. No.: </label>031 / G513