Brassey's World Aircraft & Systems Directory: 1999/2000 Edition.

World Aircraft: Origins to World War 1.

World Aircraft - Origins-World War 1.

Donald, David, The Encyclopedia of World Aircraft (pg 553).

World Aircraft - Commercial Aircraft 1935-1960.

The complete Encyclopedia of World Aircraft.

Encyclopedia of World Aircraft, p.854, "Standard aircraft".

Encyclopedia of World Aircraft, p. 854, "Standard aircraft".

Jane's All the World Aircraft 1980-81.

Airlife's World Aircraft.