P. Balister et al., IMPROVED UPPER-BOUNDS FOR THE CRITICAL PROBABILITY OF ORIENTED PERCOLATION IN 2 DIMENSIONS, Random structures & algorithms, 5(4), 1994, pp. 573-589
We refine the method of our previous paper [2] which gave upper bounds
for the critical probability in two-dimensional oriented percolation.
We use our refinement to show that p(c) < 0.6735. (C) 1994 John Wiley
& Sons, Inc.