What Was the World's First Quartz Watch? - Grail Watch
1969 Quartz Astron | Seiko Design 140
The History of Quartz Watches - First Class Watches Blog
Quartz watches, history and models - Part One
Seiko | The First Quartz Watch | The First GPS Solar Clock | The First Titanium Case Dive Watch | Astron
Seiko Watches - History, Philosophy, and Iconic Products
Astron (wristwatch) - Wikipedia
Interesting 9F write-up by SJX | WatchUSeek Watch Forums
Seiko - Monochrome Watches
Seiko Quartz-Astron] An Interesting Read: The World's First Quartz-Watch | WatchUSeek Watch Forums
The first commercial quartz watch, the Seiko Astron (courtesy of Seiko). | Download Scientific Diagram
SEIKO WATCH | Our Heritage
The Story of 1969 Quartz Astron and GPS solar Astron | Seiko Astron | Seiko Watch Corp.
A tribute to a watchmaking revolution. The 50th anniversary of the Quartz Astron is celebrated in a limited edition GPS Solar watch. | Seiko Watch Corporation
Seiko | The First Quartz Watch | The First GPS Solar Clock | The First Titanium Case Dive Watch | Astron
A Tribute To Seiko's First Quartz Watch 50 Years Ago | Quartz watch, Seiko, Quartz