| http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk | Ranfft Watch Movement Database |
| https://17jewels.info | 17jewels.info - The Movement Archive |
| 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.spareparts-watches.com/ | SpareParts-Watches (Netherlands) |
| https://welwynwatchparts.co.uk/ | Welwyn Watch Parts (UK) |
| https://www.watchys.ch/en/ | Watchys Watch Parts (Switzerland) |
| https://www.cenic-watches.ch/en/ | Cenic Watches and Parts (Switzerland) |
| https://watchesulike.com/en/ | Watches U Like Watch Parts (France) |
| https://www.kalyanediffusion89.com | KD89 Watch Parts (France) |
| https://www.daveswatchparts.com | Dave's Watch Parts (US) |
| https://www.cousinsuk.com | Cousins UK Watch Parts, Tools and Supplies (UK) |
| https://www.bergeon.swiss | Bergeon Tools and Supplies (Switzerland) |
| https://horotec.ch/home/lang/2/ | Horotec Tools and Supplies (Switzerland) |
| https://www.bijoutil.ch/en | Bijoutil Tools and Supplies (Switzerland) |