Redditor /u/hjrrockies shares a picture of a page from their copy of the first volume Foundations of Applied Mathematics. It quotes Sauron, a villain from The Lord of the Rings, saying:
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them.
It's an advanced math textbook, so the authors correctly assume that readers will be familiar with Black Speech, which is the tongue of Mordor. This particular passage is famously inscribed on the One Ring in the Elvish Tengwar script.
-via Math Lady Hazel