1. A note of welcome
2. Crossing Number is NP-Complete
3. Guy, R.K. (1960) A Combinatorial Problem. The Bulletin of the Malaysian Mathematical Society, 7, 68-72.
4. Guy, R.K. (1969) Proof Techniques in Graph Theory. Academic Press, New York.
5. Blazer, J and Koman, N. (1964) Theory of Graphs and Its Applications. Academic Press, New York.