[1]

N. Alon, Explicit Ramsey graphs and orthonormal labelings,*The Electronic Journal of Combinatorics* 1 (1994) R12.

[2]

N. Alon and Y. Peres, Euclidean Ramsey theory and a construction of Bourgain,*Acta Mathematica Hungarica* 57 (1991) 61–64.

[3]

S. Arora, C. Lund, R. Motwani, M. Sudan and M. Szegedy, Proof verification and intractability of approximation problems, in:*Proceedings of the 33rd IEEE Symposium on Foundations of Computer Science* (IEEE Computer Society Press, Los Alamitos, CA, 1992) 14–23.

[4]

S. Arora and S. Safra, Probabilistic checking of proofs; a new characterization of NP, in:*Proceedings of the 33rd IEEE Symposium on Foundations of Computer Science* (IEEE Computer Society Press, Los Alamitos, CA, 1992) 2–13.

[5]

B. Berger and J. Rompel, A better performance guarantee for approximate graph coloring,*Algorithmica* 5 (1990) 459–466.

[6]

P. Berman and G. Schnitger, On the complexity of approximating the independent set problem,*Information and Computation* 96 (1992) 77–94.

[7]

R. Boppana and M.M. Halldorsson, Approximating maximum independent sets by excluding subgraphs,*BIT* 32 (1992) 180–196.

[8]

P. Erdös, Some remarks on chromatic graphs,*Colloquium Mathematicum* 16 (1967) 253–256.

[9]

P. Erdös and G. Szekeres, A combinatorial problem in geometry,*Compositio Mathematica* 2 (1935) 463–470.

[10]

U. Feige, Randomized graph products, chromatic numbers, and the Lovász*ϑ*-function, in:*27th Annual ACM Symposium on Theory of Computing* (ACM Press, New York, 1995) 635–640.

[11]

U. Feige, S. Goldwasser, L. Lovász, S. Safra and M. Szegedy, Approximating Clique is almost NP-complete, in:*Proceedings of the 32nd IEEE Symposium on Foundations of Computer Science* (IEEE Computer Society Press, Los Alamitos, CA, 1991) 2–12.

[12]

P. Frankl and V. Rödl, Forbidden intersections,*Transactions AMS* 300 (1987) 259–286.

[13]

M. Goemans and D. Williamson, Improved approximation algorithms for maximum cut and satisfiability problems using semidefinite programming,*Journal ACM* 42 (1995) 1115–1145.

[14]

G.H. Golub and C.F. Van Loan,*Matrix Computations* (The Johns Hopkins University Press, Baltimore, 1989).

[15]

M.M. Halldorsson, A still better performance guarantee for approximate graph coloring,*Information Processing Letters* 45 (1993) 19–23.

[16]

J. Håstad, Clique is hard to approximate within*n*
^{1-ε},*Proc. 37th IEEE FOCS* (IEEE, 1996) 627–636.

[17]

M. Grötschel, L. Lovász and A. Schrijver, The ellipsoid method and its consequences in combinatorial optimization,*Combinatorica* 1 (1981) 169–197.

[18]

D. Karger, R. Motwani and M. Sudan, Approximate graph coloring by semi-definite programming, in:*35th Symposium on Foundations of Computer Science* (IEEE Computer Society Press, Los Alamitos, CA, 1994) 2–13.

[19]

R. Karp,*Reducibility among combinatorial problems*, eds. Miller and Thatcher (Plenum Press, New York, 1972).

[20]

B.S. Kashin and S.V. Konyagin, On systems of vectors in a Hilbert space,*Trudy Mat. Inst. imeni V.A. Steklova* 157 (1981) 64–67. English translation in:*Proceedings of the Steklov Institute of Mathematics* (AMS, 1983) 67–70.

[21]

D.E. Knuth, The sandwich theorem,*The Electronic Journal of Combinatorics* 1 (A1) (1994).

[22]

S.V. Konyagin, Systems of vectors in Euclidean space and an extremal problem for polynomials,*Mat. Zametki* 29 (1981) 63–74. English translation in:*Mathematical Notes of the Academy of the USSR* 29 (1981) 33–39.

[23]

L. Lovász, On the Shannon capacity of a graph,*IEEE Transactions on Information Theory* 25 (1979) 1–7.

[24]

M. Szegedy, A note on the*ϑ* number of Lovász and the generalized Delsarte bound, in:*35th Symposium on Foundations of Computer Science* (IEEE Computer Society Press, Los Alamitos, CA, 1994) 36–39.