Heidt Erhard U <br/><br/>
Instrctional media and individual letter:  : a classification and systems appraisal 

 - London:  Kogan page,  1978. 
 - 174p. 
<br/><br/> Includes index 
<br/><br/><br/>Eng 
<br/><br/><label>ISBN: </label>0850380952 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Media programs (education)<br/>Instructional technology
<br/><br/><label>Dewey Class. No.: </label>371.3078  / HEI