World Guide toTechnical Information And Documentation Services 
by Unesco,. 
 - Second edition 
 - Paris,  The Unesco Press,  1975. 
 - 515p. 
<br/><br/><label>ISBN: </label>92-3-001228-9 
<br/><br/><label>LC Class. No.: </label>T10   / .6US 1975