Notes Bibliography Buttler, Tony. Secret Projects: British Fighters and Bombers 1935 -1950 (British Secret Projects 3). Leicester, UK: Midland Publishing, 2004. . James, Derek N. Gloster Aircraft since 1917. London: Putnam, First edition, 1971. . Defunct aircraft manufacturers of the United Kingdom History of Gloucester Hawker Siddeley Companies based in Gloucester Manufacturing companies established in 1917 Industrial history of Gloucestershire 1961 mergers and acquisitions Manufacturing companies disestablished in 1963 1917 establishments in England 1963 disestablishments in England