Reference Points: Understanding The Rolex GMT-Master - Hodinkee
GMT-Master 'Captain Warren', Reference 6542 | An advert worn stainless steel dual time zone wristwatch with date and bakelite bezel | Circa 1958 | 勞力士 | GMT-Master 'Captain Warren' 型號6542 | 精鋼兩地時間腕錶備日期顯示及人造樹膠錶圈,製作年份約1958
Vintage Eye for the Modern Guy: Rolex GMT-Master II, 2018 Edition | WatchTime - USA's No.1 Watch Magazine
Rolex GMT-Master II: A History and Comprehensive Guide | Teddy Baldassarre