Douglas - The Complete Story
Mick Walker | Engels | hardcover | 176 blz | 2010
The Book of the Pre-War Douglas - All Models (1929-1939)
L.K. Heathcote | Engels | softcover | 90 blz | 2013
The Book of the Post-War Douglas - All Models (1948-1957)
Douglas Ltd. | Engels | softcover | 138 blz | 2013
The Book of 1930's British Motorcycle Gearboxes and Clutches
Engels | softcover | 118 blz | 2018