Mason, John. <br/><br/>
Developing thinking in algebra / 
John Mason, with Alan Graham and Sue Johnston-Wilder. 
 - London :  The Open University,  2005. 
 - xii, 324 p. :  ill. ;  25 cm. 
<br/><br/> Includes index. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>ISBN: </label>9781412911719 (pbk.) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Algebra--Study and teaching (Elementary)--Great Britain.<br/>Algebra--Study and teaching (Secondary)--Great Britain.