2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/139861Let G be a simple balanced bipartite graph on $2n$ vertices, $δ= δ(G)/n$, and $ρ={δ+ \sqrt{2 δ-1} \over 2}$. If $δ> 1/2$ then it has a $\lfloor ρn \rfloor$-regular spanning subgraph. The statement is nearly tight.submittedCombinatorics05C70, 05D15text