While English-speaking historians know in detail about almost every event on the BEF’s front, the same cannot be said of our knowledge of the German side of the Western Front. This is not surprising, as comparatively few English language books have been written about the German experience on the battlefields of the Great War. Recent English language scholarship by Holger Herwig, Annika Mombauer, and Robert Foley, to name but a few historians, has enriched our understanding of the conflict. However, these works have tended to concentrate on political and diplomatic history, or in the case of Mombaurer and Foley, on high-ranking officers such as Helmuth von Moltke and Erich von Falkenhayn. This means that events at the tactical and operational level remain comparatively unexplored in English. This gap in the historiography has largely been shaped by the absence of primary source materials.
Humphries, Mark Osborne "The First Use of Poison Gase at Ypres, 1915: A Translation from the German Official History." Canadian Military History 16, 3 (2007)