A guide to the operation of the agreement for facilitating the international circulation of visual and auditory materials of on educational, scientific and cultural character : "Beirut Agreement 

 - 2a ed. 
 - Paris : UNESCO, 1969. 
 - 31 p. 
<br/><br/><label>No. de Clasificación Universal Decimal: </label>OC 341.24: 008 (100)=20 "1969" GUI.