Crystal, David. <br/><br/>
Advanced Conversational English /  

 - 1st ed /  
 - England :   Longman Group Ltd. ,   1983 
 - p.132 :  
<br/><br/><label>ISBN: </label>0-582-55074-2 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Linguistics
<br/><br/><label>Dewey Class. No.: </label>P111  / L5