* "The Congo Report of Commission of Inquiry" (New York, 1906)* Czekanowski, in "Zeitschrift für Ethnologie", pages 591–615 (1909)* Grant, Kevin, "A Civilised Savagery: Britain and the New Slaveries in Africa, 1884–1926", Routledge (London, 2005).
* "The Congo Report of Commission of Inquiry" (New York, 1906)* Czekanowski, in "Zeitschrift für Ethnologie", pages 591–615 (1909)* Grant, Kevin, "A Civilised Savagery: Britain and the New Slaveries in Africa, 1884–1926", Routledge (London, 2005).