"Book(s) on WWII Artillery tactics?" Topic

I am looking to go deeper than equipment and anecdote and into more detail on the chain of communication from the observer to the battery and how fire missions were set up and executed. Preferably all armies, and looking at the details on how it was employed.

This web site nigelef.tripod.com covers the field artillery organisation, tactics, gunnery methods and regiments of the British & Commonwealth – whilst it isn't a book I printed its pages and put them in a binder (and I am not one for printing stuff…).