Unesco <br/><br/>
World information report 1977/1978 

 - N.d. 
 - Paris  UNITED NATIONS EDUCATIONAL SCIENTIFIC AND CULTURAL ORGANIZAT  1997 
 - 390p p. 
<br/><br/><label>ISBN: </label>92-3-103341-7 
<br/><br/><label>Dewey Class. No.: </label>02.621  / UNESCO