“Liberty V12 Engine”. darwinsairwar.com.au. Darwins Aviation Museum. January 29, 2017閲覧。
neam.org
“Liberty 12A V-12”. New England Air Museum. April 15, 2013時点のオリジナルよりアーカイブ。March 30, 2013閲覧。
oldrhinebeck.org
“Cole Palen's Old Rhinebeck Aerodrome - Aircraft Engines - Page 4 - Liberty”. oldrhinebeck.org. Rhinebeck Aerodrome Museum. March 4, 2016時点のオリジナルよりアーカイブ。February 22, 2016閲覧。 “Produced in large numbers and used extensively in mail planes following the War, the Liberty was a significant U.S. contribution to aviation. Jesse Vincent of Packard and E.J. Hall of Hall-Scott designed the engine in five days. One month later the first prototype was built and running.”
“Cole Palen's Old Rhinebeck Aerodrome - Aircraft Engines - Page 4 - Liberty”. oldrhinebeck.org. Rhinebeck Aerodrome Museum. March 4, 2016時点のオリジナルよりアーカイブ。February 22, 2016閲覧。 “Produced in large numbers and used extensively in mail planes following the War, the Liberty was a significant U.S. contribution to aviation. Jesse Vincent of Packard and E.J. Hall of Hall-Scott designed the engine in five days. One month later the first prototype was built and running.”