Grolier academic encyclopedia. 

 - US :  Grolier,  1987. 
 - Vols. :  ill. ;  25 cm. 
<br/><br/>V. 4-- ; 
<br/><br/>400  400 
<br/><br/><label>ISBN: </label>0-7172-2017-6 
<br/><br/><label>Subjects--Geographic Terms: </label><br/>United States --Encyclopedias.
<br/><br/><label>Dewey Class. No.: </label>031 / G513