I. Podgorny, M. Cannon, and T. Goodyear. Proceedings of the 18th ACM Conference Companion on Computer Supported Cooperative Work and Social Computing (CSCW '15 Companion), Vancouver, Canada, page 143--146. New York, ACM, (2015)
R. Popp, D. Montana, R. Gassner, G. Vidaver, and S. Iyer. IEEE International Conference on Systems, Man, and
Cybernetics, 3, page 2184--2189. San Diego, CA USA, IEEE, (11-14 October 1998)