Gunnar Tornqvist, Editor. Division of Labour, Specialization, and
Technical Change: Global, Regional, and Workplace Level. Malmo,
Sweden: Liber, 1986.

Marcella Corsi. Division of Labour, Technical Change, and
Economic Growth. Aldershot, Hants, U.K.: Avebury/Brookfield VT:
Gower Publishing Co., 1991.

Leonard Bloomfield. Language. 1933. rpt. New York: Holt, Rinehart & Winston. 1964.

In this work, the author maintains that the division of labor, and with it the whole working of human society, is due to language.

Charles Sanders Peirce. "Anything that determines something else (its interpretant) to refer to an object to which itself refers (its object) in the same way, the interpretant becoming in turn a sign, and so on ad infinitum" (2.303). "Something which stands to somebody in some respect or capacity" (2.228).

Other sign definitions have been given: "In the language, reciprocal presuppositions are established between the expression (signifier) and the expressed (signified). The sign is the manifestation of these presuppositions," (A. J. Greimas and J. Courtés, Semiotics and Language. An Analytical Dictionary, Bloomington: Indiana University Press, 1983, p. 296; translation of Sémiotique. Dictionnaire Raisonné de la Théorie du Langage, Paris: Classique Hachette, 1979).

According to L. Hjelmslev, the sign is the result of semiosis taking place at the time of the language act. Benveniste considers that the sign is representative of another thing, which it evokes as a substitute.

Herbert Marcuse. The One-Dimensional Man. Studies in the Ideology of Advanced Industrial Society. Boston: Beacon Press, 1964.

Plato. Phaedrus, and The Seventh and Eighth Letters (translated from the Greek), with an introduction by Walter Hamilton. Harmondsworth: Penguin Press, 1973.

Regarding cave paintings, see: