Does anyone know is this a real book?

I am currently reading Lady Oracle by Margaret Atwood, and within the book, a reference is made to a book called "The Fox" (no author name given) said to be about the Borgias. With my general interest in historical fiction and my particular interest in the Italian Renaissance, I was intrigued and wanted to look the book up, but I have not been able to find anything. There was no obvious reason to suspect this book title fictionalized by Atwood, but it is possible.

So I was wondering if anyone knows anything about such a book and if it really exists or not.

Could it be Prince of Foxes by Samuel Shellabarger? It is historical fiction about the Borgias family, written in 1947.

That could possibly be it, as not much information is given. There is just one line that mentions one of the characters reading "The Fox" a historical novel about the Borgias. But that is all it says about it.

Based on what I read it does sound like that Prince of Foxes is a strong likely candidate, as the main character in Lady Oracle is an author of escapists historical romance, and when I looked up "Prince of Foxes" it does sound like the type of books that the woman in Lady Oracle herself writes, so it would fit in.

This book was made into a movie with Tyrone Power, Everett Sloan, and I believe Orson Welles. A black and white movie which captures the mood of the Borgias. I saw it years ago, but I have never been able to find a digital version, VHS or DVD. Welles plays Caesar Borgia who tells the Sloan character to blind Power by using his thumbs to pop out his eyeballs. Sloan does this, supposedly, then shows them to Welles, but he hasn't harmed Power. What he holds up for Welles to view is a pair of crushed grapes.

Apparantly it's now available on DVD:
http://www.imdb.com/title/tt0041767/board/nest/66992201

Yes!!! this is a real book :)