Tull D S <br/><br/>
Marketing research 
Tull D S; Hawkins D I 
 - 4 
 - New York  New York, Macmillan  1987 
 - 845p 
<br/><br/><label>ISBN: </label>0-02-421910-X 
<br/><br/><label>Source: </label>Textbook