(g,f)-Factors and f-factors with constraints in bipartite graphs

Let G=(X,Y,E) be a bipartite graph and let g and f be two positive integer functions defined on V(G) with(g(x))f(x) for each x∈V(G).It is proved that if a G is the (mg,mf-1)-graph and M is a mathing with m edges,then G has a(g,f)-factor containing an edge of M and excluding other edges of M.If G is the(2m-1)-edge connected bipartite(mf)-graph,then G has an f-factor containing any given edge and excluding any given m-1 edges.