Unwin, Derick.  <br/><br/>
The encyclopaedia of educational media communications and technology / 
Derick Unwin and Ray McAleese. 
 - London :  Macmillan,  c 1978. 
 - xviii, 800 p. :  ill. ;  23 cm. 
<br/><br/>322  322 
<br/><br/><label>ISBN: </label>0-333-18550-1 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Educational technology--Dictionaries.
<br/><br/><label>Dewey Class. No.: </label>371.307803 / E19