1. Hamiltonian cycles in regular graphs, Ann.;Bollobás;Discrete Math.,1978
2. Properties of graphs with constraints on degrees;Bondy;Studia Sci. Math. Hungr.,1969
3. On Hamilton's ideals;Chvátal;J. Combinatorial Theory,1972
4. Tough graphs and hamiltonian circuits;Chvatal;Discrete Math.,1973
5. Some theorems on abstract graphs;Dirac;Proc. London Math. Soc.,1952