Bibliografia
Principal
- · J. M. Howie, "Automata and Languages", Clarendon Press, Oxford (1991). · J. M. Howie, "Fundamentals of Semigroup Theory", Oxford University Press (1996). · M. V. Lawson, "Finite Automata", Chapman&Hall/CRC (2004). · J.-E. Pin, "Varieties of Formal Languages", North Oxford, London, and Plenum, New York (1986).: