Gurdev Singh <br/><br/>
Information sources, services and systems 

 - Delhi  PHI Learning  2013 
 - xviii, 517p.   
<br/><br/> Includes bibliographical references and index 
<br/><br/><label>ISBN: </label>9788120346390 
<br/><br/><label>Subjects--Topical Terms: </label><br/>E-sources<br/>Information services and systems<br/>Information sources<br/>Ready reference sources<br/>Reference services