Bondy, J. A. "Pancyclic Graphs I." J. Combin. Th.11, 80-84, 1971.Meyniel, M. "Une condition suffisante d'existence d'un circuit hamiltonien dans un graphe orienté." J. Combin. Th.14, 137-147, 1973.Ore, Ø. "Note on Hamilton Circuits." Amer. Math. Monthly67, 55, 1960.Palmer, E. M. "The Hidden Algorithm of Ore's Theorem on Hamiltonian Cycles." Computers Math. Appl.34, 113-119, 1997.Woodall, D. R. "Sufficient Conditions for Circuits in Graphs." Proc. London Math. Soc.24: 739-755, 1972.