Near the end of the video, you mentioned more information is available about quaternions in a Chapter 3 reference. I did not catch the full of the reference. Can you send me this?
I googled the dvd, but I only found one that isn't made by Beorn. But by Nathan
https://www.youtube.com/playlist?list=PLE211C8C41F1AFBAB
Beorn if you reading it, I'll also like to know the dvd you've mentioned in the end of the video.
