1. Abranches, H. (1991). Sobre os Basolongo: Arqueologia da tradição oral. Gent: Fina Petróleos de Angola.
2. Andah, B. W. (1995). Early urban societies and settlements of the Guinea and savannah regions of West Africa. West African Journal of Archaeology, 25(1), 103–152.
3. Axelson, S. (1970). Culture confrontation in the lower Congo: From the Old Congo Kingdom to the Congo Independent State with special reference to the Swedish missionaries in the 1880’s and 1890’s. Falköping: Gummessons.
4. Bairoch, P. (1988). Cities and economic development: From the dawn of history to the present. Chicago: The University of Chicago Press.
5. Bentley, H. M. (1907). W. Holman Bentley: The life and labours of a Congo pioneer. London: The Religious Tract Society.