Suggestions for WWI books

It's pretty difficult to find WWI books (compared to WWII, for example). I've read your typical ones, All Quiet on the Western Front, etc). I'd love to read a book/novel that is less known but is really poignant, or first about the front lines rather than purely politics or from perspectives outside the war itself. I've watch a lot of documentaries, but I love to read. Any suggestions are welcomed!