Books about Siege warfare

Attack of Fortified Places. Including Siege-works, Mining, and Demolitions.

The Attack in Trench Warfare: Impressions and Reflections of a Company Commander

Elements of Trench Warfare

Training for the Trenches

Trench Warfare: A Manual for Officers and Men

Handy War Guide for My Company: Handy Company Commander's Guide

Notes on Training for Rifle Fire in Trench Warfare