Decomposition of balanced complete bipartite multigraphs into multistars

In this paper, we obtain a criterion for the decomposition of the λλ-fold balanced complete bipartite multigraph λKn,nλKn,n into (not necessarily isomorphic) multistars with the same number of edges. We also give a necessary and sufficient condition of decomposing 2Kn,n2Kn,n into isomorphic multistars.