Ackermann, W., Solvable cases of the decision problem, North-Holland, Amsterdam, 1954.
Ershov, Yu. L., Lavrov, I. A., Taimanov, A. D. and Taitslin, M. A., Elementary theories, Russian Mathematical Surveys, vol. 20 (1965), pp. 35–106.
Gabbay, D., Sufficient conditions for the undecidability of intuitionistic theories, this Journal, vol. 37 (1972), pp. 375–384.
Gabbay, D., Decidability of some intuitionistic predicate theories, this Journal, vol. 37 (1972), pp. 579–587.
Heyting, A., Intuitionism; an introduction, 2nd edition, North-Holland, Amsterdam, 1966.
de Jongh, D. H. J., The maximality of the intuitionistic predicate calculus with respect to Heyting's arithmetic, Compositio Mathematica (to appear).
Kleene, S. C., Logical calculus and realizability, Acta Philosophica Fennica, vol. 18 (1965), pp. 71–80.
Kreisel, G., Elementary completeness properties of intuitionistic logic with a note on negations of prenex formulae, this Journal, vol. 23 (1958), pp. 317–330.
Kreisel, G., Notes concerning the elements of proof theory, Course Notes, University of California, Los Angeles.
Kreisel, G. and Krivine, J. L., Elements of mathematical logic (model theory), North-Holland, Amsterdam, 1967.
Kripke, S., Semantical analysis of intuitionistic logic. I, Formal systems and recursive functions (Crossley, J. N. and Dummett, M. A. E., Editors), North-Holland, Amsterdam, 1965.
Kripke, S., Semantical analysis of intuitionistic logic. II (unpublished).
Leivant, D., A note on translations of C into I, Mathematisch Centrum, Amsterdam, Technical Report, 1971.
Lifshits, V. A., Deductive validity and reduction classes, Studies in constructive mathemattes and mathematical logic, Part 1 (Slisenko, A. O., Editor), Consultants Bureau, New York, 1969.
Lifshits, V. A., Problem of decidability for some constructive theories of equalities, Studies in constructive mathematics and mathematical logic, Part 1 (Slisenko, A. O., Editor), Consultants Bureau, New York, 1969.
Lifshits, V. A., Constructive mathematical theories consistent with classical logic, Problems in the constructive trend in mathematics. IV (Orevkov, V. P. and Shanin, N. A., Editors), American Mathematical Society, Providence, R.I., 1970.
Lopez-Escobar, E. G. K., A decision method for the intuitionistic theory of successor, Indagationes Mathematicae, vol. 30 (1968), pp. 466–467.
Maslov, S. Yu., Mints, G. E. and Orevkov, V. P., Unsolvability in the constructive predicate calculus of certain classes of formulas containing only monadic predicate variables, Soviet Mathematics, Doklady, vol. 6 (1965), pp. 918–920.
Mints, G. E. and Orevkov, V. P., An extension of the theorems of Glivenko and Kreisel to a certain class of formulas of predicate calculus, Soviet Mathematics, Doklady, vol. 4 (1963), pp. 1365–1367.
Orevkov, V. P., On Glivenko sequent classes, The calculi of symbolic logic, American Mathematical Society, Providence, R.I., 1971.
Rabin, M. O., Decidability of second order theories and automata on infinite trees, Transactions of the American Mathematical Society, vol. 141 (1969), pp. 1–35.
Rogers, H. Jr., Certain logical reduction and decision problems, Annals of Mathematics, vol. 64 (1956), pp. 264–284.
Rose, G., Propositional calculus and realizability, Transactions of the American Mathematical Society, vol. 75 (1953), pp. 1–19.
Scott, D., Extending the topological interpretation to intuitionistic analysis, Compositio Mathematica, vol. 20 (1968), pp. 194–210.
Scott, D., Extending the topological interpretation to intuitionistic analysis. II, Intuitionism and proof theory (Kino, A., Vesley, R. and Myhill, J., Editors), North-Holland, Amsterdam, 1970.
Smorynski, C., The undecidability of some intuitionistic theories of equality and order this Journal, vol. 36 (1971), pp. 587–588.
Tarski, A., Mostowski, A. and Robinson, R. M., Undecidable theories, North-Holland, Amsterdam, 1953.