388 REFERENCES
Karp, R. M. (1972), Reducibility among combinatorial problems, in Compkx-
ity of Computer Computations, Miller, R. and Thatcher, J., &is., Plenum
Press, New York, pp. 85-103.
Kelley, D. (1995) A u t omata and Formal Languages, Prentice-Hall, Upper
Saddle River, NJ.
Knuth, D. (1981) The Art of Computer Programming, Vol. 2, Seminumerical
Algorithms (2nd Ed.), Addison-Wesley, Reading, MA.
Lawler, E. L. (1976) Coinbinatorial Optimization: Networks and Matroids,
Holt, Rinehart and Winston, New York.
Lewis, H. R. and Papadimitriou, C. H. (1998) Elements of the Theory of
Computation (2nd ed.), Prentice-Hall, Upper Saddle River, NJ.
Li, M. and Vitanyi, P. (1997), An Introduction to Kolmogorov Complexity and
Its Applications (2nd ed.) , Springer-Verlag , Berlin.
Linz, P. (2001) An Introduction to Formal Languages and Automata (3rd
Ed.), Jones and Bartlett, Sudbury, MA.
Machtey, M. and Young, P. (1978), An Introduction to the General Theory of
Algorithms, North-Holland, Amsterdam.
Martin, J. C. (1991) Introduction to Languages and the Theory of Computa-
tion, McGraw-Hill, New York.
Minsky, M. L. (1967) Computation: Finite and Infinite Machines, Prentice-
Hall, Upper Saddle River, NJ.
Papadimitriou, C. H. (1994) Computational Complexity, Addison-Wesley,
Reading, MA.
Rogers, H., Jr. (1967) Theory of R ecursive Functions and Effective Com-
putability, Mc-Graw Hill, New York.
Salomaa, A. (1973) F ormal Languages, Academic Press, New York.
Savage, J. E. (1998) Models of Computation, Addison-Wesley, Reading, MA.
Sipser, M. (1997) Introduction to the Theory of Computation, PWS Publish-
ing Co., Boston.
Soare, R. I. (1987) R ecursively Enumerable Sets and Degrees, Springer-Verlag,
Berlin.
Sudkamp, T.A. (1997), Languages and Machines, Addison-Wesley, Reading,
MA.
Taylor, R. G. (1998) Models of Computation and Formal Languages, Oxford
University Press, New York.