Do you remember the book? I remember loving Alvin's Secret Code, which was on the bookshelf in my fourth-grade classroom where I sat in the back to be near the bookshelf...
Sorry, no. But it would have been a 70s or 80s publication. I recall there were several Cold War code stories, so it might have been on this subject. Like popular history stories, one after the other—you thought that was crazy? Check out this hollow nickel! But all very serious like.
