Books Dedicated to Improving your GMing Skills

So, lately as I was working on my GM's Guide to Guiding Actions I compiled a list of books that are dedicated to improving your GMing Skills (that are not part of a game system).

This is the complete list below (or you can watch it in Google Spreadsheet), Let me know if I missed anything

Roleplay-English

The Stairwell System

(or “How to remember everything that happened in the session”) In episode 18 of On the Shoulders of Dwarves I’ve briefly mentioned how I use