"Powell, L. S." <br/><br/>
Guide to the use of visual aids 

 - London  British Association for Commerical and Industrial Education   0 
 - 36 p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Traning and teaching
<br/><br/><label>Dewey Class. No.: </label>371.335 POW