Organizations relating to watch collecting
National Association of Watch and Clock Collectors
Educational links
Paul Schliesser phenomenal site on the Gruen Company
Article on the Gruen Company at Wikipedia
Mike Barnett's site contains a lot of information on the company. He is also a source for ALL things Gruen (publications, watches, parts, etc.).
Watches for Sale
Bruce Shawkey's fine watches - Lots of Gruen watches
Watches of the Guild - both great information and watches for sale
Other watch forums with Gruen Discussions
Disclaimer
Links provided to not constitute an endorsement of the site (commercial or otherwise). Links are provided as a service and as point of interest to Gruen Collectors.