Werner Kuich. Semirings: A basis for a mathematical automata and language theory. In Symeon Bozapalidis, editor, Proceedings of the 3rd International Conference Developments in Language Theory, DLT 1997, Thessaloniki, Greece, July 20-23, 1997. pages 49-60, Aristotle University of Thessaloniki, 1997.
Abstract is missing.