Post & Telecommunications Corporation. Commemorative Envelope with Rhodesia and Nyasaland Stamps Marking 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/).  