Nick Georgano: The Beaulieu Encyclopedia of the Automobile. Volume 3: P–Z. Fitzroy Dearborn Publishers, Chicago IL 2001, ISBN 1-57958-293-1 (englisch).
David Culshaw & Peter Horrobin: The Complete Catalogue of British Cars 1895–1975. Veloce Publishing plc. Dorchester (1997), ISBN 1-874105-93-6