https://www.watch-wiki.net//a> Watch Wiki
https://ranfft.org Ranfft-based Watch Movement Database (post Roland Ranfft - RIP Roland!)
https://17jewels.info 17jewels.info - The Movement Archive
https://calibercorner.com Caliber Corner
https://www.crazywatches.pl Crazy Watches
https://www.vintagewatchstraps.com/casemarks.php David Boettcher's Extensive Historical Research of Case Marks and Hallmarks
https://www.mikrolisk.de Mikrolisk Horological Trademark Database
http://www.830-1000.dk/british_marks.html Online Encyclopedia of Silver Marks, Hallmarks and Maker's Marks
https://watchguy.co.uk/cgi-bin/files Watch Guy UK Technical Manuals
https://watchlibrary.org The Watch Library Periodical Archive
https://www.watchrepairtalk.com Watch Repair Talk Forum
https://www.cousinsuk.com Cousins UK Watch Parts, Tools and Supplies (UK)
https://welwynwatchparts.co.uk/ Welwyn Watch Parts (UK)
https://gleave.london Gleave and Co (UK)
https://www.esslinger.com Esslinger (US)
https://www.daveswatchparts.com Dave's Watch Parts (US)
https://watchesulike.com/en/ Watches U Like Watch Parts (France)
https://www.kalyanediffusion89.com KD89 Watch Parts (France)
https://www.spareparts-watches.com/ SpareParts-Watches (Netherlands)
https://www.bergeon.swiss Bergeon Tools and Supplies (Switzerland)
https://www.watchys.ch/en/ Watchys Watch Parts (Switzerland)
https://www.cenic-watches.ch/en/ Cenic Watches and Parts (Switzerland)
https://horotec.ch/home/lang/2/ Horotec Tools and Supplies (Switzerland)
https://www.bijoutil.ch/en Bijoutil Tools and Supplies (Switzerland)
https://salondeshorlogers.ch Salon des Horlogers - A mission to promote artisanal watchmaking