Bell, Robert J.T.. <br/><br/>
Elementary Treatise on Coordinate Geometry of three dimensions /  

 - Third Ed. /  
 - London WC2 :   Macmillan and Company Ltd.. 
 - p.377,xlviii :  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics 
<br/><br/><label>Dewey Class. No.: </label>B63:23  / H4;3