Thomson , A J; Martinet ,A. V. <br/><br/>
A Practical English Grammar Exercises  2 

 - 3rd 
 - Oxford  : Oxford-University  1996 
 - 199 
<br/><br/><label>ISBN: </label>0-19-431350-6 
<br/><br/><label>Subjects--Personal Names: </label><br/>Humanity & Natural Sciences
<br/><br/><label>Subjects--Topical Terms: </label><br/>Humanities and Natural sciences