Gupta ,rl and gupta v.k <br/><br/>
Vitiya lekhankan 

 - New delhi  Sultan chand and sons  2009 
 - s.137p 
<br/><br/><label>ISBN: </label>978-81-8054-558 
<br/><br/><label>Dewey Class. No.: </label>657H    Gup p9