Cyclable Cubic Of A Graph

The cyclability of graphs is a generalization of Hamiltonian. A graph G is said to be cyclable if for each orientation D of G, there exists a set S(D) (?) V(G) such that revising all the arcs with one end in S results in a Hamiltonian digraph. In this paper, we show that the cubic of a connected graph with at least five vertices is cyclable if and only if this graph is not isomorphic to any even path. This improves three results of Klostermeyer et al.