1. Chang, C. C.,Algebraic analysis of many-valued logics. Trans. Amer. Math. Soc.88 (1958), 467?490.
2. Chang, C. C.,A new proof of the completeness of Lukasiewicz axioms. Trans. Amer. Math. Soc.93 (1959), 74?80.
3. Lukasiewicz, J. andTarski, A.,Untersuchungun �ber den Aussagenkalk�l, Comptes Rendus des S�ances de la Soci�t� des Sciences et des Lettres de Varsovie. Classe III, vol.23 (1930), 30?50.
4. Belluce, L. P.,Semi-simple algebras of infinite valued logic and bold fuzzy set theory. Can. J. Math. XXXVIII, No. 6 (1986), 1356?1379.
5. Mangani, P.,On certain algebras related to many-valued logics (Italian). Boll. U.M.I. (4),8 (1973), 68?78.