From the introduction:
This homebrew works refers to previous editions books on the Gaijin nations and updates them for 4th edition. It also refers a lot to 7th Sea, but in no way is meant to endorse the fact that Théah is in the same world as Rokugan. I just used it as inspiration for Thrane and Merenae and to allow easier references for descriptions for readers, since I’ll be rather short on those. Some of the information comes from the L5r wikia for the LBS content, as I couldn’t track down every card from this game. Everything else is based on the released books and novels for L5r. The cover art was done by the artist Shosuro Akae, done for the previous guide I did back in 2006, of 140 pages long describing the Burning Sands. This guide is a sequel of sorts. The others pictures come from Imperial Histories 1, Exotic Arms and Equipments and the LBS and L5R CCGs.