Kleene, S. C. "The Deduction Theorem." §21 in Introduction
to Metamathematics. Princeton, NJ: Van Nostrand, pp. 90-94, 1964.Monk,
D. J. Mathematical
Logic. New York: Springer-Verlag, p. 118, 1976.Robbin,
J. W. "The Deduction Theorem." §21 in Mathematical
Logic. New York: W. A. Benjamin, pp. 16-20, 1969.Shoenfield,
J. R. "The Deduction Theorem." §3.3 in Mathematical
Logic. Reading, MA: Addison-Wesley, pp. 33-34, 1967.