United Nations. Economic and Social Council; United Nations. Economic Commission for Africa; UN. ECA Conference of Ministers Meeting (16th : 1990, May 15 - 19 : Tripoli, Libyan Arab Jamahiriya); UN. ECA (25th session : 1990, May 15 - 19 : Tripoli, Libyan Arab Jamahiriya); UN. ECA Technical Preparatory Committee of the Whole Meeting (11th : 1990, May 5-12 : Tripoli, Libyan Arab Jamahiriya) (1990-04)