Many books Namedrop other books within their books they referenced in research, or even for pop-culture relevance. It should be possible to link these references as directly being mentioned within the book you just read.

So for example, in Octavia E. Butler’s “A Few Rules for Predicting the Future”, she references “The Rise and Fall of the Third Reich” as having been an inspiration for her works in science fiction.

In John Fugelsang’s Separation of Church & Hate, he references “A People’s History of Christianity”.

It doesn’t even have to be research related, it could be as obscure as being a book mentioned within a fictional story that a character refers to as having read.

This would be ideal to show in a row before other recommendations once you’ve read the book, allowing you to continue to explore the subject area or the author’s inspiration they recommended within their text, but is otherwise unavailable to find without re-reading the part in which they made the reference.