Chopra, J. K. <br/><br/>
Unique quintessence of statistical analysis graphs and diagrams  For UPSC/PCS civil services examination / 

 -  Unique pub ,  2008. 
 - P.E-168 
<br/><br/><label>ISBN: </label>818357131X 
<br/><br/><label>Subjects--Index Terms: </label>Competitive Exam Guide