Having run into several references, at various places and occasions, to "Serre’s Course at Collège de France, 19xy-19xy+1" for various values of xy, I would genuinely like to know where these lectures are written down and archived.
Has there been an effort to preserve them in any form?
There are overviews of them in Serre’s collected work, but they have no references and don’t give full proofs.