Whenever I've needed to relearn some of the base operations that we do in the tutorials so far, I've gone and read through the relevant sections from the Foundation of Game Engine Development books. They've been a fantastic resource for me, and they inspired the sections on covering the infinite projection matrix as well as using reverse depth for your projection matrixes/depth buffer for greater precision far away from the camera. Both techniques I had heard of, but never implemented or used myself. If you're interested in the deeper math behind how all of this works, or even just want to skim for things like the formulas and code snippets, I can't recommend them enough.
I'm not sure if we'll cover the topics, but towards the end of Volume 1, it touches on Grassman Algebra. I won't pretend to understand it myself, but it's a more natural way to get to the same end state as Quaternions. At time of writing I've not decided if I want to cover Rotors, which is the primary part of the section we'd be interested in, and have never studied them previously. If we do end up covering them, or you're interesting yourself, make sure to take a look at the end of Volume 1 here. If you'd like to go very in-depth, that's where I'd recommend the Projective Geometric Algebra Illuminated book. Not something I've looked at myself yet, but for the more mathy among you, it may be of interest!
I'll try to add some good online resources as well, it's not as though I've never looked at any, but I wanted to mention at least the first 2 books which have been a one stop shop for re-learning math I've not done in about 8 years.