Mark Stefik Daniel G. Bobrow Gregg Foster Stan Lanning Deborah G. Tatar WYSIWIS Revised: Early Experiences with Multiuser Interfaces. 147-167 1987 5 ACM Trans. Inf. Syst. 2 http://doi.acm.org/10.1145/27636.28056 db/journals/tois/tois5.html#StefikBFLT87