Paul Zimmerman S. Joy Mountford Dominic Milano Peter Mitchell Thecla Schiphorst Paul Zimmerman 385-388 1991 CHI https://doi.org/10.1145/108844.108959 conf/chi/1991 db/conf/chi/chi1991.html#MountfordMMSZ91 Dominic Milano Peter Mitchell S. Joy Mountford Thecla Schiphorst