Article date: Aug 1972
Article title: The curious properties of the Gray code and how it can be used to solve puzzles
Mathematical Games column? Y
Book: 11. Knotted Doughnuts and Other Mathematical Entertainments
Chapter: 2. The Binary Gray Code
This data confirmed? yes
Notes
Peter Rowlett (27 August 2022):
Peter Rowlett initial guess (Uncertain)
Peter Rowlett (1 November 2023):
I have seen this chapter and column side-by-side and they match.