Chapter 8 sample pdf has a typo(?) in the first paragraph. Carl Hewitt's last name is spelled both Hewitt and "Hewitz", maybe even in the same sentence.

Using an accumulation parameter with tail recursion was per Wikipedia introduced in one of the LTU papers, sometime before Scheme. So the description in the chapter is at best imprecise. But, I would want to look further back historically to see whether any Algol compilers used the technique.

Overall the book looks readable as an intro to Lisp and Lisp implementation, but in a history book I'd like to see more precision and depth, careful citations, etc.