Tom Bohman Alan M. Frieze Tomasz Luczak Oleg Pikhurko Clifford D. Smyth Joel Spencer Oleg Verbitsky First-Order Definability of Trees and Sparse Random Graphs. 375-400 2007 16 Combinatorics, Probability & Computing 3 http://dx.doi.org/10.1017/S0963548306008376 db/journals/cpc/cpc16.html#BohmanFLPSSV07