Germany. Heer
Free to read here, from Project Gutenberg.
Histories of two hundred and fifty-one divisions of the German army which participated in the war (1914-1918)
With the German armies in the West
Operations Upon the Sea: A Study
Germany and the Next War
Germany's Fighting Machine
'Jena' or 'Sedan'?
A Little Garrison: A Realistic Novel of German Army Life of To-day
Life in a German Crack Regiment
Ein Volk in Waffen
Deductions from the World War