We introduce a mixed model for the Web graph that simultaneously describes the inlink and outlink distributions by taking into account the interconnection of the two processes. We derive an expression for the steady-state distribution of indegrees (outdegrees) among vertices with fixed outdegree (indegree) in terms of sums of beta functions. Experimentation on subsets of the real Web shows that the proposed distributions well reproduce the behavior of the observed data.
"A Coupled Model for the Indegree and Outdegree Analysis of the Web." Internet Math. 6 (4) 437 - 459, 2010.