(written from a Production point of view)
In a deleted scene from ENT: "The Expanse", Languages of the Sub-Sahara was a book owned, but not read, by Hoshi Sato in 2153. While preparing to embark to the Delphic Expanse, Sato decided to send this book, among others, back to her mother, in order to make more space for books on alien languages.
The book was sold off, along with a number of other items belonging to Sato, on the It's A Wrap! sale and auction on eBay.  A different book with the same title was also included in this listing, but doesn't appear to have made it on screen.