Collins work on your grammar.  Intermediate B1. 

 - London :  Collins,  2013. 
 - 127 pages ;  28 cm. 
<br/><br/> Formerly CIP. 
<br/><br/><label>ISBN: </label>9780007499625 (pbk.) :  £9.99 
<br/><br/><label>Nat. Bib. No.: </label>GBB2A4177  bnb 
<br/><br/><label>Nat. Bib. Agency Control No.: </label>016190516  Uk 
<br/><br/><label>Subjects--Topical Terms: </label><br/>English language--Grammar--Textbooks for foreign speakers.<br/>English language--Grammar--Examinations, questions, etc.