McGraw-Hill,  . <br/><br/>
Encyclopedia of Science and Technology Vol-5 /  

 - Reprinted 1971 /  
 - New York :   McGraw-Hill Book Company. 
 - p.635 :  
<br/><br/><label>ISBN: </label>07-079798-6 
<br/><br/><label>Dewey Class. No.: </label>AK73,N60  / L1.5