"Organisationsgeschichte der deutschen Heeresartillerie im II. Weltkrieg"
which can be seen as the 'Bible' on topic german artillery in WW2!
More in german on Panzer-Archviv
I am one of those happy ones that received the first test print Volumes

Much work spent in archives and in tons of NARA Rolls by the author, you can see that on every page!
Only 500 sets will be printed, only avaiable via Uwe himself.
I recommend to put your bet on it as soon as possible!
Jan-Hendrik