I want to read philosophy papers that analyze the logical connective "but", and contrasts it with "and". I once read a paper that talked about this topic, but I can't find it anymore.
Humberstone's epic tome The Connectives is always a good place to start for such questions. While "but" isn't treated directly, Humberstone does spend a couple pages (674-676) giving references on the topic. Sweetser 1990 and Rudolph 1996 seem especially interesting on the philosophical/linguistic side of things. On the mathematical side Humberstone says that there isn't as much material but references Francez 1995 and Meyer/van der Hoek 1996, and this MathOverflow question provides some further context.