Letter dated 17 August 1967 from the Ministers for Foreign Affairs of Bulgaria, the Byelorussian Soviet Socialist Republic, Cuba, Czechoslovakia, Hungary, Mongolia, Poland, the Ukrainian Soviet Socialist Republic and the Union of Soviet Socialist Republics addressed to the Secretary-General
Letter dated 17 August 1967 from the Ministers for Foreign Affairs of Bulgaria, the Byelorussian Soviet Socialist Republic, Cuba, Czechoslovakia, Hungary, Mongolia, Poland, the Ukrainian Soviet Socialist Republic and the Union of Soviet Socialist Republics addressed to the Secretary-General