- U.S. Geological Survey Geographic Names Information System: Estill, Missouri
- "Post Offices". Jim Forte Postal History. Archived from the original on 9 October 2016. Retrieved 8 October 2016.
- Eaton, David Wolfe (1916). How Missouri Counties, Towns and Streams Were Named. The State Historical Society of Missouri. p. 175.
- "Howard County Place Names, 1928–1945 (archived)". The State Historical Society of Missouri. Archived from the original on 24 June 2016. Retrieved 8 October 2016.CS1 maint: BOT: original-url status unknown (link)