Harrogate Terriers. The 1/5th (Territorial) Battalion West Yorkshire Regiment in the Great War
There is a Foreword by Peter Hart.
This is a comprehensive study of this Territorial battalion's war, written by someone who appears to have been a "semi-professional" military historian.
The book is well written, with many plans, maps, and (some very interesting and unusual) images.
Haig commented that the West Yorkshire Territorials were "too sleepy to fight well". This battalion proved him wrong.