McGregor, Jim. <br/><br/>
The BBC Micro Book BASIC, Sound and Graphics /  

 - 1st ed /  
 - London :   Addison-Wesley Publishing Company ,   1989 
 - p349 :  
<br/><br/><label>ISBN: </label>0-201-14058-6 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Sound System
<br/><br/><label>Dewey Class. No.: </label>Bv  / M3