The world book encyclopedia. 

 - 1988 ed. 
 - Chicago :    World Book, Inc.,    1988 
 - V. 1-21 :    ill. ;    25 cm. 
<br/><br/><label>ISBN: </label>0716600889 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Encyclopedias and dictionaries.
<br/><br/><label>Dewey Class. No.: </label>031