Fiume Benue Superiore—Flegel—Società Missionaria Chiesa—Nigeria—Camerun—RGS 1880 mappa
'Part of Central Africa North of the Equator, from the general map of Africa by Keith Johnston, F.R.G.S. // Map of the Upper Binué River, from a survey by Mr. E. R. Flegel of the Church Missionary Society’s Expedition, 1879.'.