As a non-law fluent person, this was the best resource to understand what the law says about legal libraries in prisons. If you are looking for the same information. This should be your first stop! Sources are so abundant that the notes on each page of this book are more than half of the page which includes further information such as cases and laws with quoted text.
I’m not really comfortable to talk about what the law is right now, but what I found interesting that could apply to non-legal libraries is the following quote:
Courts understand that a “cell delivery” or “paging” system, by itself, does not provide adequate court access because prisoners who cannot visit the library generally will not know what materials to ask for. If prison officials do permit segregation inmates to have physical access to the law library, that access must be adequate. (242)
This might make us rethink how delivery services to hospital and mental health (and other) locations in the prison system might be improved for better access. For example, bringing a cart full of books might be better suited in addition to books requested from patrons instead of just the requested reads.
Boston, John and Daniel Manville. Prisoners’ Self-Help Litigation Manual. 4th ed. Oxford: Oxford University Press, 2010.