Practical statistics 
By S.P. Gupta 
 - 7th rev ed. 
 - New delhi:  S. Chand & company ltd.,  1994. 
 - viii,560p. 
<br/><br/><label>ISBN: </label>81-219-0624-5 
<br/><br/><label>Subjects--Index Terms: </label>Commerce Practical statistics 
<br/><br/><label>Dewey Class. No.: </label>519.5