The World book student discovery science encyclopedia ( Vol.6 ) : 

 - Chicago  World Book  2007 
 - 224p.  ( Vol. 6 ) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Science-Dictionaries
<br/><br/><label>Dewey Class. No.: </label>503 WOR ( 6 )