Authors include Tragastch, Bourdache, Peter Henshaw, Bob Currie, Roy Bacon and Ken Hallworth. See Bibliography
Magazines and journals include
The Motor Cycle, Motor Cycling, Classic Motorcycle and many others
Extensive information about the magazine collection at Classic Motorcycle Memorabilia
Motor Sports Magazine have archives dating back to 1920s.
Jonathon Hayt of Arizona
Paul Markham of Australia, Eugene Smith of Arkansas
Byron Bay Motorcycles, Australia
Immagina by Gyp
Rick Zolla, Montanaman
Roger Henderson, Yorkshire
Todd Koehn, WI
Dave Morgan, Australia
Robert Livingstone, Argentina
Pekka Puoskari, Finland.
See Collectors & Enthusiasts
Club Ydral, JLB-Creations, Cycle Memory, Chez Alice, Les Vieilles Chaînes Villefranchoises, Thierry Heurlin, François-Marie Dumas, Velosolex, Les Monet-Goyon & Koehler-Escoffier sur le Net...
Moto di Lombardia, Milan region.
Motoclubstoricoconti.it Italian marque information
Bill Irwin of thebikemuseum.com
Jon Bertelli: Maserati
Franco Bonadonna, Itom
Colin Jones, Itom
The GTU has a large database of German manufacturers.
Horst Mennig, Denia
DKW Motorrad Club
Virtuelles Kraftfahrzeug Museum Austria (voz.co.at)
Motorradveteranenclub Attnang Puchheim
raketsport.com has information on numerous models from the prodigious Scandinavian manufacturer Crescent.
The Moped Army has tomes of literature about the mighty moped.
Wolverhampton History & Heritage Website Jampot Simply masses of information about AJS and Matchless
Barnstormers NZ Excellent page from the Shaky Isles.
motorbike-search-engine.co.uk has been helpful with data on many antique machines.
Belgian Motorcycle Rally images courtesy Erard of Oldtimersweb.be
Craig Howell of thecreeper.net
Monet Goyon and other images courtesy The Naked Maicomobil
Superia courtesy superiabromfietsen.be
Information on Swedish marques from an archive of www.konditori100.se, and also from bjorns-story.se
Atlas Cards whose archive of collector cards has been enormously helpful. More about Atlas here: Classic Motorcycle Memorabilia
Open Source information
Archivio dell’Enciclopedia italiana
Istituto per i beni artistici culturali e naturali
Wikipedia including Wikipedia NL
Archive.org Includes a fascinating set of pages from The Motor Cycle of 1922, reproduced with acknowledgement to Mortons Motorcycle Media, holders of the copyright for "The MotorCycle" and "Motorcycling".
Grace's Guide contains a wealth of knowledge concerning British motorcycles.
Apologies to the many who as yet lack attribution.