We define a new invariant tB(G) in bipartite graphs that is analogous to the toughness t(G) and we give sufficient conditions in term of tB(G) for the existence of k-factors in bipartite graphs. We also show that these results are sharp.
International Journal of Mathematics and Mathematical Sciences
Sun, J. Z.,
(2008). Bipartite Toughness and the k-Factors in Bipartite Graphs. International Journal of Mathematics and Mathematical Sciences, 2008.
Available at: https://aquila.usm.edu/fac_pubs/15402