Books in World War I (sorted alphabetically by author)
- War and the Weird Forbes Phillips and R. Thurston Hopkins
- The Better Germany in War Time: Being Some Facts Towards Fellowship Harold W. Picton
- Trapped in 'Black Russia': Letters June-November 1915 Ruth Pierce
- A Short History of the Great War A. F. Pollard
- The Discipline of War John Hasloch Potter
- Fighting in Flanders E. Alexander Powell
- The New Frontiers of Freedom from the Alps to the Ægean E. Alexander Powell
- The Iron Division, National Guard of Pennsylvania, in the World War H. G. Proctor
- A Noble Woman: The Life-Story of Edith Cavell Ernest Protheroe
- England and the War Sir Walter Alexander Raleigh
- Army Boys on German Soil: Our Doughboys Quelling the Mobs Homer Randall
- Army Boys in France; or, From Training Camp to Trenches Homer Randall
- Army Boys on the Firing Line; or, Holding Back the German Drive Homer Randall
- Army Boys in the French Trenches; Or, Hand to Hand Fighting with the Enemy Homer Randall
- Cannes und Genua: Vier Reden zum Reparationsproblem (German) Walther Rathenau
- Tell England: A Study in a Generation Ernest Raymond
- Night Bombing with the Bedouins Robert Henry Reece
- Der rote Kampfflieger (German) Freiherr von Manfred Richthofen
- Canada in Flanders, Volume III Sir Charles G. D. Roberts
- The Story of the "9th King's" in France Enos Herbert Glynne Roberts
- Rogers-isms, the Cowboy Philosopher on the Peace Conference Will Rogers
- War in the Garden of Eden Kermit Roosevelt
- Three years in France with the Guns: Being Episodes in the life of a Field Battery C. A. Rose
- The Story of the 2/4th Oxfordshire and Buckinghamshire Light Infantry Geoffrey Keith Rose
- Everyday Foods in War Time Mary Swartz Rose