Uberlieferte Strickmuster is a 3 volume set of books by Maria Erlbacher. I believe they've been out of print for some time. They are kind of a holy grail for people who are into twisted stitches. As you may have guessed from the title, the books are all written in German.
I had heard that Schoolhouse Press was going to reissue the books in English. I had no idea that they were available until I happened upon Twisted Stitch Knitting while shopping online at Webs. The books have been consolidated into a single volume. This one's on top of my Christmas list. Also my Amazon wish list, because they've got it, too.
What the heck are twisted stitches and why would someone want to twist them? You know how a knit stitch looks like two parallel lines? In twisted knitting, they look a bit more like an X. Most instructions I've seen tell you to knit through the back leg of the stitch. I knit in a weird manner so knitting through the front leg gets me the X. This serves to raise the stitch up off of the surface a bit and makes some extremely cool-looking patterns. This bit of Bayerische might give you an idea of what it looks like. Click the Bayerische link for a much better look.