I'm addicted to buying art and reference books and I just got another called Uniforms of WWI. It has tons of illustrations and pictures. I wish there were more photos because sometimes details are lost in the artist's interpretation, but overall it seems like it'll help a great deal with coming up with new Rivet uniforms. It even has me thinking of the looks for the other nations that are part of the allies and blighters. I'd also like to do a horse mounted unit and maybe something like that crazy dog towed machine gun.