Lynda Hardman, Dick C.A. Bulterman, and Guido van Rossum
Links in hypermedia: the requirement for context
In: Fifth ACM Conference on Hypertext Proceedings (Hypertext'93)
Seattle, Washington pp. 183-191
ACM Press, November 14-18, 1993
See also: ht93.
Available at http://www.cwi.nl/ftp/mmpapers/ht93.ps.gz