Below is a list of primary source books published on the subject of the Congo Free State and the movement for Congo reform.
American Congo Reform Association. Conditions in the Congo State. Washington, D.C.: Judge and Deyweiler, 1904.
American Congo Reform Association. The Latest Phase of the Congo Question. Baltimore: The Sun Book and Job Printing Office, 1906.
Conan Doyle, A. Crime of the Congo. London: Hutchinson & Co., 1909.
Burrows, G. & Canisius, E. The Curse of Central Africa. London: R.A. Everett & Co., 1903.
Morel, E. D. History of the Congo Reform Movement. Oxford: Clarendon Press, 1968.
Morel, E. D. King Leopold’s Rule in Africa. London: William Heinemann, 1904.
Morel, E. D. The Congo Slave State. Liverpool: John Richardson and Sons, 1902.
Starr, F. The Truth about the Congo. Chicago: Forbes and Company, 1907.
Twain, M. King Leopold’s Soliloquy. Boston: The P.R. Warren Co., 1905.