The classic text of Deligne and Rapoport giving a model for the mod p reduction of the modular curve is found in a "Lecture Notes in Mathematics" volume.
Has it been translated from the original french and/or LaTeX-ed so that it can be searched more easily?
I would be extremely surprised if there existed a translation or a LaTeX version. I have a searchable pdf of it though. Annoying Megaupload link: http://www.megaupload.com/?d=F6GBYUBU