The World book encyclopedia volume 21 :  W-X-Y-Z / 

 - 510 pages :  illus. (part col.), images, figures, maps ;  26 cm. 
<br/><br/>Includes bibliographies. 
<br/><br/><label>ISBN: </label>0716600749 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Encyclopedias and dictionaries.
<br/><br/><label>LC Class. No.: </label>AE5  / .W55 1972 
<br/><br/><label>Dewey Class. No.: </label>031  / W893