Brownlie, Ian; Ian R. Burns (1979). "Botswana-Zambia (Quadripoint issue)". African Boundaries: A Legal and Diplomatic Encyclopaedia. London: C. Hurst & Co. pp. 1098–1108. ISBN0-903983-87-7.; summarized at African tripoints: Botswana-Namibia-Zambia by Michael Donner / Jesper Nielsen.