[1] J. F. Baldwin: Fuzzy logic and fuzzy reasoning. Internat. J. Man-Mach. Stud. 11 (1979), 465-480. MR 0542593 | Zbl 0418.03014

[2] C. C. Chang, H. J. Keisler: Continuous Model Theory. Princeton University Press, Princeton 1966. MR 0231708 | Zbl 0149.00402

[3] C. C. Chang, H. J. Keisler: Model Theory. North-Holland, Amsterdam 1973. Zbl 0276.02032

[4] B. R. Gainess: Foundations of fuzzy reasoning. Internat. J. Man-Mach. Stud. 8 (1976), 623-668. MR 0574083

[5] J. A. Goguen: The logic of inexact concepts. Synthese 19 (1968-69), 325-373.

[6] V. Novák: Fuzzy Sets and Their Applications. Adam Hilger, Bristol 1989. MR 1019090

[7] V. Novák, W. Pedrycz: Fuzzy sets and t-norms in the light of fuzzy logic. Internat. J. Man-Mach. Stud. 28 (1988).

[8] V. Novák: On the syntactico-semantical completeness of first-order fuzzy logic. Part II: Main results. Kybernetika 26 (1990), No. 2 (to appear). MR 1059796

[9] J. Pavelka: On fuzzy logic I, II, III. Z. Math. Logik Grundlag. Math. 25 (1979), 45-52; 119-134; 447-464. MR 0524558

[10] H. Rasiowa, R. Sikorski: The Mathematics of Meta-mathematics. PWN, Warszawa 1963.

[11] J. R. Shoenfield: Mathematical Logic. Addison-Wesley, New York 1967. MR 0225631 | Zbl 0155.01102