I have just added the English translation of Bruchmuller's work "Die Artillerie bieim Angriff im Stellungskreig" to the Research and Resources page of Lovett Artillery. I hope you enjoy this.
May I recommend David T. Zabecki's book "Steel Wind - Col. Georg Bruchmuller and the Birth of Modern Artillery" - as I remember not hugely expensive and supplies the biographical details and context of Bruchmuller's work.
Many people would think Bruchmuller's doctrines in WW1 to be impossibly obscure now but one army that did continue to develop his ideas was the Red Army - later the Russian Army after the fall of the USSR. Even today the Russian use of artillery in Eastern Ukraine has echoes of Bruchmuller.