There are a couple dozen of them listed on ebay right now.
That's where I got mine. They seem to be a LOT cheaper now. Just do your search for 1997 Taurus manual. The SHO is included in Ford's factory manual for ALL Tauri. I like a paper copy that I can take to the garage with me, but CD manuals are also available. Be sure to get a FORD factory manual. Haynes and Chilton just don't cut it.