I'm aware of the rules of thumb (around 3,000 - 5,000 words, depending on whom you ask), but has this actually been written in a credible manual for writers that can be cited (not a website)?
There are various factors which determine 'ideal' length - and these include cost factors, publishers' preferences/experiences, and readership preferences.
I wouldn't be surprised if an 'ideal' chapter:work length were to connect in some way to a mathematical part:whole ratio like the Golden Section, as Don Paterson argues in relation to sonnet structure in the introduction of his 101 Sonnets collection.
There is a short section on how to estimate length for a non-fiction book proposal (based on multiplying the average length of the sample chapters by the proposed number of chapters in the envisaged book), and giving an estimated page range for the MS based on a 'standard 250 words per double-spaced page' in Elizabeth Lyon's Nonfiction Book Proposals Anybody Can Write (Perigree: NY, 2002, 171).
You might contact Writer's Digest, who publish extensively on the topic of writing and publishing and put the question to them.
If a manual wrote an answer to your question, I wouldn't consider it credible. There isn't an answer that fits every, or even most books, because writing is a craft that relies on people making decisions about things such as where to end chapters.
You don't specify if you are talking about fiction or non-fiction. If you are writing fiction you need to consider things like cliffhangers, pace and structure.
If you are writing non-fiction, you have to consider the genre: coffee table book, PHD thesis, etc.
Why do you need something that can be cited that isn't a website?