Address by Federico Mayor at the opening of the International Forum on Sustainable Development, París, 23 September 1991 / 
United Nations Educational, Scientific and Cultura Organization. 
 - París :  UNESCO,  1991. 
 - 6 p. 
 - DG 91 ;  28 .
<br/><br/><label>Encabezamiento--Nombre Corporativo: </label><br/>Unesco