Kaddoura Sam <br/><br/>
Echo made easy 

 - 1st 
 - Edinburgh  Churchill livingstone (elsevier)  2002 
 - 190 
<br/><br/><label>ISBN: </label>0443061890 
<br/><br/><label>Dewey Class. No.: </label>616.1207547  / KAD/EC