On Potentially K2,2,1,1-graph Graphic Sequences

For given a graph H, a graphic sequence pi = (d(1), d(2), ..., d(n)) is said to be potentially H-graphic if there exists a realization of pi containing H as a subgraph. In this paper, we characterize the potentially K-2,K-2,K-1,K-1-graphic sequences where K-r,K-s,K-p,K-t is an r x s x p x t complete 4-partite graph. Up to now, characterization of potentially complete 4-partite graph with k(k <= 6) vertices has solved.