The New Book of Knowledge: O 

 - U. S. A.  Grolier Incorporated  1999 
 - 307 pages ;  col. ill ;  26 cm. 
<br/><br/> includes index. 
<br/><br/><label>ISBN: </label>0-7172-0530-4 
<br/><br/><label>Dewey Class. No.: </label>R/031.083/N42/1999/V14