1. C. C. Chang. Algebraic analysis of many-valued logics, Trans. Amer. Math. Soc., 88, 467 – 490, 1958.
2. C. C. Chang. A new proof of the completeness of the Lukasiewicz axioms. nuns. Amer. Math. Soc., 93, 74 – 80, 1959.
3. R. Cignoli, I. M. L. D’Ottaviano and D. Mundici. Algebras of Lukasiewicz Logics, (in Portuguese). Collection CLE, Vol. 12, Center of Logic, Epistemology and History of Science, State University of Campinas, UNICAMP, SP, Brazil, Second Edition, 1995. Expanded edition in English, in preparation.
4. A. Di Nola. MV-Algebras in the Treatment of Uncertainty. In Proceedings of the International IFSA Congress, Bruxelles 1991. P. Löwen and E. Roubens, eds. pp. 123 – 131. Kluwer, Dordrecht, 1993.
5. M. R. Garey and D. S. Johnson. Computers and Intractability, A Guide to the Theory of NP-completeness. W. H. Freeman and Company, San Francisco, 1979.