Commercial mathematics and statistics 
By N.K. Nag 
 - 6th ed. 
 - Ludhiana:  Kalyani publishers,  2012. 
 - x,464p. 
<br/><br/><label>ISBN: </label>978-81-272-6225-9 
<br/><br/><label>Subjects--Index Terms: </label>Arithmetic Commercial mathematics and statistics 
<br/><br/><label>Dewey Class. No.: </label>513