H. Enderton, A Mathematical Introduction to Logic, Academic Press, 1972
J. Avigad, Computability and Incompleteness : Lecture Notes
J. R. Shoenfield, Mathematical Logic, Addison-Wesley Pub. Co, 1967
E. Schimmerling, A Course On Set Theory, Cambridge University Press, 2011
C. C. Chang and H. J. Keisler, Model Theory. 3rd ed., North-Holland, 1990