These proceedings have long been freely available on the AMS website, but now it seems we can't even find them anymore (e.g. http://www.ams.org/publications/online-books/pspum331-index and http://www.ams.org/publications/online-books/pspum332-index). Unfortunately, I don't own a copy, nor have I ever downloaded it on my computer. My question, then: Does anyone know if there exists another website where I could get it?
Given the importance of the proceedings, I leave a link to the copy at Library Genesis:
A. Borel and W. Casselman (Editors) Automorphic Forms, Representations and L-functions (1979)