Weaver, Gilbert G. and Bollinger, Elroy W. <br/><br/>
Visual aids their construction and use 

 - New York  D.van nostrand  1949 
 - 388p. 
<br/><br/><label>ISBN: </label>  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Education<br/>Method of instruction
<br/><br/><label>Dewey Class. No.: </label>371.3  / WEA