Noga Alon Jehoshua Bruck Explicit Constructions of Depth-2 Majority Circuits for Comparison and Addition. 1-8 1994 7 SIAM J. Discrete Math. 1 http://epubs.siam.org/sam-bin/dbq/article/21849 db/journals/siamdm/siamdm7.html#AlonB94