Unlocking secrets of the unknown with National Geographic / 
prepared by the Book Division, National Geographic Society. 
 - Washington, D.C. :  The Society,  c1993. 
 - 200 p. :  ill. (some col.) ;  27 cm. 
 - 910/.9 .
<br/><br/> Includes index. 
<br/><br/><label>Subjects--Corporate Names: </label><br/>National Geographic Society (U.S.)
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geography--Research.
<br/><br/><label>Dewey Class. No.: </label>910/.9