1. An unsolvable problem of elementary number theory, Preliminary report (abstract);Church;Bull. Amer. Math. Soc,1935
2. An unsolvable problem of elementary number theory, Amer;Church;J. Math.,1936
3. A note on the Entscheidungsproblem;Church;J. Symbolic Logic,1936
4. Review of Turing [1936];Church;J. Symbolic Logic,1937