1. Recent Progress in Combinatorics;Barnette,1969
2. Examples and Counterexamples in Graph Theory;Capobianco,1978
3. Graph Theory;Harray,1969
4. On hamiltonian circuits;Tutte;Canad. J. Math.,1946
5. A theorem on planar graphs;Tutte;Trans. Amer. Math. Soc.,1956