Ullman, Jeffrey D.. <br/><br/>
Principles of Database Systems /  

 - Second Ed. /  
 - New Delhi-60 :   Galgotia Publications. 
 - p484 :  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Database systems
<br/><br/><label>Dewey Class. No.: </label>Bv  / M8