Comparative handbook of Congo languages: being a comparative grammar of the eight principal languages spoken along the banks of the Congo river from the west coast of Africa to Stanley Falls, and of Swahili, the 'lingua franca' of the country stretching thence to the east coast
Among Congo cannibals: experiences, impressions and adventures during thirty years' sojourn amongt the Boloki and other Congo tribes, with a description of their curioes habits, customs, religion and laws