|AviationHeritage.org - Working to document aviation heritage and history through the use of modern technologies|
|Curtiss P-40F, Lockheed Hudson, and CAC Boomerang (Daniel J. Leahy, 2014)|
Baugher, J. 2018 1940 USAAC Serial Numbers. Joe Baugher's Home Page. Retrieved 1 April 2018 from <http://www.joebaugher.com/usaf_serials/1940.html>.
Pacific Wrecks 2018 A-20A "Spook" Serial Number 40-109. Retrieved 2 April 2018 from <https://www.pacificwrecks.com/aircraft/a-20/40-109.html>.
Record updated on 2 April 2018.