"September 1985." "In J. Carroll (ed.), Interfacing thought : cognitive aspects of human computer interactions, ... l986."

"December 1986." "Published in the Proceedings of the Conference on Computer-Supported Cooperative Work, Austin, Texas, December 3-5, 1986."

"April 1985." "This paper appeared in the Proceedings of the CHI'85 Conference on Human Factors on Computing Systems, ... San Francisco, CA, April 14-18, 1985."--P. [5]

"December, 1986." "A slightly revised version of this paper will appear in Communications of the ACM."