Russell, Bertrand. <br/><br/>
ABC of Relativity /  

 - Third Rev Ed. /  
 - London WC1A 1LU :   George Allen & Unwin Ltd.. 
 - p.160 :  
<br/><br/><label>ISBN: </label>0-04-521002-0 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Relativity
<br/><br/><label>Dewey Class. No.: </label>CN  / L7