I've been reading through a PDF on my Kindle Scribe which I downloaded from the original site --- it's a great overview, and most importantly, includes citations and references to the various papers where folks shared their research/progress.

These days of course, one would just get _The Essentials of CAGD_ and similar texts, or read: https://pomax.github.io/bezierinfo/ or watch: https://www.youtube.com/watch?v=jvPPXbo87ds

Highly recommended for anyone who wants an understanding of how modern CAD software came about.

For my part, I have found it invaluable in working on my current project as described at: https://news.ycombinator.com/item?id=43159236