Agreement between the government of the United Kingdom of Great Britain and Northern Ireland and the government of Northern Rhodesia concerning the employment of certain officers in the public service of Northern Rhodesia : signed at London, 11 January 1962 and at Lusaka, 30 January 1962 (the agreement is deemed to have entered into force on 1 April 1961) (Zambia (Great Britain. Commonwealth Office) ;, 1968)