Magnús M. Halldórsson, Jaikumar Radhakrishnan, K. V. Subrahmanyam. Directed vs. Undirected Monotone Contact Networks for Threshold Functions. In 34th Annual Symposium on Foundations of Computer Science, 3-5 November 1993, Palo Alto, California, USA. pages 604-613, IEEE, 1993.
Abstract is missing.