Exton, William <br/><br/>
Audiovisual aids to instruction / 
by William Exton 
 - New York :  Mc Graw-Hill,  1947 
 - 344 p. ;  26 cm. 
<br/><br/> Includes index 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Visual education<br/>Education