Wittich, Walter A. <br/><br/>
Instructional technology :  its nature and use. 

 - 6th. 
 - New York :  Harper and Row,  1979. 
 - xx, 331p. 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0060471697 
<br/><br/><label>Subjects--Topical Terms: </label><br/>teaching aids.<br/>Educational technology.<br/>Educational technology.