Thomson, A J. Martinet, A V. <br/><br/>
Practical English grammar 

 - 4th ed. 
 - New Delhi  Oxford University Press  1986 
 - 383 
<br/><br/><label>ISBN: </label>9780195620535 
<br/><br/><label>Dewey Class. No.: </label>425  THO;1  R