A Grammar of contemporary English / 
by Randolph Quirk ... (et al.) 
 - Essex :  Longman,  1972 
 - xii, 1120 p. :  ill. ;  24 cm. 
<br/><br/>p. 1083-1091 
<br/><br/><label>ISBN: </label>058252444X 
<br/><br/><label>LCCN: </label>72-189941 
<br/><br/><label>Subjects--Topical Terms: </label><br/>English language--Grammar