Noga Alon Michael Krivelevich Benny Sudakov Tura'n Numbers of Bipartite Graphs and Related Ramsey-Type Questions. 477-494 2003 12 Combinatorics, Probability & Computing 5-6 db/journals/cpc/cpc12.html#AlonKS03 http://dx.doi.org/10.1017/S0963548303005741