Impact :  a guide to business communication /  
Northey, Margot . 
 - 6th ed 
 - Toronto:  Pearson /Prentice Hall ,  2005. 
 - vii,294 p,: 
<br/><br/><label>ISBN: </label>0131219197 
<br/><br/><label>LC Class. No.: </label>HF5718  / .N67  2005