1. Archivio Generale dei Missionari d’Africa (A.G.M.Afr.): White Fathers’ Archive, Rome, Italy.
2. Council for World Missions/London Missionary Society (CWM/LMS): London Missionary Society Archive, School of Oriental and African Studies, London, UK.
3. Zanzibar National Archives (ZNA): Zanzibar National Archives, Zanzibar Town, Zanzibar, Tanzania.
4. Alpers, Edward A. Ivory & Slaves in East Central Africa: Changing patterns of international trade to the later nineteenth century. London: Heinemann, 1975.
5. Alpers, Edward A. ‘The ivory trade in Africa: An historical overview,’ in Elephant: The animal and its ivory in African culture, ed. Doran H. Ross. Los Angeles: Regents of the University of California, 1992.