You would probably have to get a printed booklet from North Texas RPG Convention in Dallas when you see them on sale. I'll take a look at the back of it when I get home, but I thought it was printed by Lulu.com at one point. The main Planet Eris rulebook is really just a house-ruled version of the Little Brown Books (0e) with a mix of material/guidance from the Basic/Expert/Companion/Immortal set of D&D books from 1980-1982. If you are interested in running your own Planet Eris game I could probably help you with the material you would need.
