Millman, Peter M.. <br/><br/>
This Universe of Space /  

 - 1st ed /  
 - London E.C.4 :   Routledge & Kegan Paul Ltd.. 
 - p.117 :  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics 
<br/><br/><label>Dewey Class. No.: </label>B9  / K3;1