Quirk, Randolph <br/><br/>
A university grammar of English / 
Randolph Quirk, Sidney Greenbaum 
 - ELBS ed. 
 - Harlow :  English Language Book Society and Longman,  1979 
 - 484 p. ;  23 cm. 
<br/><br/>p.462-464 
<br/><br/><label>ISBN: </label>0582559448 
<br/><br/><label>Subjects--Topical Terms: </label><br/>English language--Grammar--1950-