1. [1] R. Carraghan, P. M. Pardalos, An exact algorithm for the maximum clique problem, Operation Research Letters9 (1990), 375–382. ⇒135
2. [2] M. R. Garey, D. S. Johnson, Computers and Intractability: A Guide to the Theory of NP-completeness, Freeman, New York, 2003. ⇒132
3. [3] P. R. J.Östergård, A fast algorithm for the maximum clique problem, Discrete Applied Mathematics120 (2002), 197–207. ⇒135
4. [4] C. H. Papadimitriou, Computational Complexity, Addison-Wesley Publishing Company, Inc., Reading, MA 1994. ⇒132
5. [5] N. J. A. Sloane, Challenge Problems: Independent sets in graphs, http://neilsloane.com/doc/graphs.html ⇒140