Britannica Global Edition 
Dale H.Hoiberg and  Michael Levy 
 - Chicago  Encyclopaedia Britannica,Inc  2011 
 - 14592P.:ill 
<br/><br/><label>ISBN: </label>978-1-62513-418-9 
<br/><br/><label>Dewey Class. No.: </label>032  / H719 V.24