Good, engagingly written books on Gladio?
I recently went down a rabbit hole about Roberto Calvi, the banker that ended up hanging from Blackfriars Bridge and the entire backstory seemed like right out of an Umberto Eco novel. Between freemasons and the Vatican, I kept stumbling over references to Operation Gladio. Now, I know what Gladio basically was, but apparently there is quite a lot I've never heard about. Can you recommend good books on the subject? I don't care too much if written by a journalist or a historian, as long as it is well-researched and well-written. Preferably taking a wider view on Italy's Years of Lead and Europe in general.
Thank you so much in advance!