Encyclopaedia, Britannica <br/><br/>
Yearbook of science and the future 1983 

 - Encyclopaedia Britannica, Inc., Chicago  1982 
 - 445 
<br/><br/><label>ISBN: </label>0-85229-397-6 
<br/><br/><label>Dewey Class. No.: </label>R503 E.B.Y.