I believe I have a textbook at home on this already. This particular text: is it noteworthy because it was highly influential? Or is it especially well written?

I believe I have a textbook at home on this already. This particular text: is it noteworthy because it was highly influential? Or is it especially well written? Or because it takes an unusual perspective on the topic? At first glance, I find the explicit modelling of these systems as state machines to be interesting. We used state machines when I learned about it as well, but didn’t call as much attention to it. The extra attention — I like that