1. Church, A.Introduction to mathematical logic, vol. 1, Princeton, 1956.
2. Herbrand, J. Sur la théorie de la demonstration,Comptes Rendus des Séances de l'Académie des Sciences (Paris),186 (1928), 1274–1276.
3. Montague, R.Contributions to the axiomatic foundations of set theory, deposited in the University of California Library, Berkeley.
4. Montague, R. and Kalish, D. A simplification of Tarski's formulation of the predicate calculus (abstract),Bull. Amer. Math. Soc., 62 (1956), 261.
5. Montague, R. and Kalish, D. Formulations of the predicate calculus with operation symbols and descriptive phrases (abstract),Bull. Amer. Math. Soc., 62 (1956), 261.