?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.aufirst=David&rft.aulast=Walker&rft.au=Walker%2C+David&rft.title=The+Interface+is+the+system%3A+Update+on+the+Xerxes+project&rft.date=May+2010&rft.genre=proceeding