Post & Telecommunications Corporation. Envelope with Rhodesia and Nyasaland Stamps Commemorating the Centenary of David Livingstone’s Sighting of Victoria Falls in 1855, 19 June 1955. Images copyright Christoffel Kok. Creative Commons Attribution-NonCommercial 3.0 Unported (https://creativecommons.org/licenses/by-nc/3.0/).  