^Crowell, Benedict; Wilson, Robert Forest (1921). The Armies of Industry II: our nation's manufacture of munitions for a world in arms, 1917-1918. New Haven: Yale University Press. p. 670.
^Mroz, Albert (2009). American Military Vehicles of World War I: an illustrated history of armored cars, staff cars, motorcycles, ambulances, trucks, tractors and tanks. Jefferson: MacFarland & Company Inc. p. 245. ISBN978-0-786-4-3960-7.