DAS , B.C . <br/><br/>
HIGHER SECONDARY CO-ORDINATE SOLID GEOMETRY  

 - 13TH. 
 - KOLKATA  U.N.DHAR & SONS  1998 
<br/><br/><label>Subjects--Index Terms: </label>Geometry 
<br/><br/><label>Dewey Class. No.: </label>516 DAS