Jorge Almeida: Finite semigroups and universal algebra.
World Scientific 1994, 510p. Very important - see review in ZB.

1112 Michael Arbib: Algebraic theory of machines, languages, and semigroups.
Academic Press 1968.

7906 Michael Arbib/John Rhodes/Bret Tilson: Complexity and group complexity
of finite-state machines and finite semigroups. In 1112 Arbib, 127-145.

15365 Beverly Austin/Karsten Henckell/Chrystopher Nehaniv/John
Rhodes: Subsemigroups and complexity via the presentation lemma.
J. Pure Appl. Algebra 101 (1995), 245-289.

15365 Beverly Austin/Karsten Henckell/Chrystopher Nehaniv/John
Rhodes: Subsemigroups and complexity via the presentation lemma.
J. Pure Appl. Algebra 101 (1995), 245-289.

15426 D. Paul Benjamin: Formulating systems. Internet ca. 1995, 4p.

15427 D. Paul Benjamin: On the emergence of intelligent global
behaviors from simple local actions. Internet ca. 1999, 19p.

14226 Aldo De Luca/Stefano Varricchio: Finiteness and regularity in
semigroups and formal languages. Springer 1999, 240p. $45.

1103 Samuel Eilenberg: Automata, languages, and machines A.
Academic Press 1974.

1104 Samuel Eilenberg: Automata, languages, and machines B.
Academic Press 1974.

7866 Karl Folley (ed.): Semigroups. Academic Press 1969.

15419 Andrew Gleason: Semigroups of shift register matrices.
Math. Systems Theory 25 (1992), 253-267. From a course given at
Princeton in 1960.

15367 T. Hall/Mark Sapir: Idempotents, regular elements and sequences
from finite semigroups. Discrete Math. 161 (1996), 151-160.

10563 Kenneth Krohn/Richard Mateosian/John Rhodes: Complexity of ideals
in finite semigroups and finite-state machines.
Math. Systems Theory 1 (1967), 59-66.

Kenneth Krohn/John Rhodes: Results on finite semigroups derived from the
algebraic theory of machines. Proc. Nat. Ac. Sci. USA 53 (1965), 499-501.

7886 Kenneth Krohn/John Rhodes: Algebraic theory of machines I. Prime 
decomposition theorem for finite semigroups and machines.
Trans. AMS 116 (1965), 450-464.

7912 Kenneth Krohn/John Rhodes: Complexity of finite semigroups.
Annals Math. 88 (1968), 128-160.

7905 Kenneth Krohn/John Rhodes/Bret Tilson: The prime decomposition theorem
of the algebraic theory of machines. In 1112 Arbib, 81-125.

7907 Kenneth Krohn/John Rhodes/Bret Tilson: Axioms for complexity of finite
semigroups. In 1112 Arbib, 233-267.

15418 Gerard Lallement/Robert McFadden: On the determination of
Green's relations in finite transformation groups.
J. Symb. Comp. 10 (1990), 481-498.

15422 S. Linton/G. Pfeiffer/E. Robertson/N. Ruskuc: Groups and actions
in transformation semigroups. Math. Zeitschr. 228 (1998), 435-450.

15420 S. Linton/G. Pfeiffer/E. Robertson/N. Ruskuc: Computing
transformation semigroups. J. Symb. Comp. 33 (2002), 145-162.

11599 Robert McNaughton: The finiteness of finitely presented monoids.
Internet 1997, 15p.

Marston Morse/G. Hedlund: Unending chess, symbolic dynamics and a problem
in semigroups. Duke Math. J. 11 (1944), 1-15.

Chrystopher Nehaniv: Complexity of finite aperiodic semigroups and star-free
languages. In Almeida a.o. 1996, 195-209.

15366 Chrystopher Nehaniv: From relation to emulation - the covering
lemma for transformation semigroups.
J. Pure Appl. Algebra 107 (1996), 75-87.

John Rhodes: Some results in finite semigroups. J. Algebra 4 (1966), 471-504.

7867 John Rhodes: Algebraic theory of finite semigroups.
In 7866 Folley, 125-162.

John Rhodes: A homomorphism theorem for finite semigroups.
J. Math. Syst. Theory 1 (1967), 289-304.

John Rhodes: Complexity and characters of finite semigroups.
J. Comb. Theory, ca. 1968.

John Rhodes: The fundamental lemma of complexity for arbitrary finite
semigroups. Bull. AMS 74 (1968), 1104-1109.

15421 Nik Ruskuc: Computational semigroup theory (past and present).
Internet 1997, 25p.

7868 Bret Tilson: Appendix to "Algebraic theory of finite semigroups".
On the p length of p-solvable semigroups. Preliminary results.
In 7866 Folley, 163-208.