In Fahrenheit 451, according to Beatty’s account of the history of society, what four reading items did the “old‟ public let survive?

I can actually only find reference to two types of reading
matter that were allowed to survive in the quick lecture that Beatty gives Montag about
the history of society and how it naturally erased books and reading matter from its
consciousness. As Montag is lying "sick" in bed, Beatty visits him and tells him and us
the history of their world and how reading books has become such a crime in this
society. Notice what he says regarding permissible reading
material:

But
the public, knowing what it wanted, spinning happily, let the comic books survive. And
the three-dimensional sex magazines, of
course.

So, we can see that
the society allowed pornography and comic books to survive the cull of reading material,
reflecting the intellectual depths to which they plummetted and the kind of society that
we see presented in this novel: a society based on instant gratification of lusts and
desires rather than serious, thoughtful, introspective
meditation.