AutoCAD Expert's Visual LISP: Release 2019 Edition.

I'm a huge fan of this author. His vLISP books are extremely well structured, thorough, and correct. His subject matter expertise and passion for the subject are undeniable. This is an essential reference for intermediate/advanced vLISP developers to reach the next level. I can't recommend this book enough. Get his AutoCAD 2021 VS Code Update kindle book to supplement this book as it's the definitive reference for the Autodesk VS Code AutoLISP extension.

Great book with many valuable tools.