The book was included in the ACM's Classic Book series, but a free PDF was not available until now. Backstory here: <a href="https://mcjones.org/dustydecks/john-allen-1937-2022-and-anatomy-of-lisp" rel="nofollow">https://mcjones.org/dustydecks/john-allen-1937-2022-and-anat...</a>