1. Behmann, Heinrich, Beiträge zur Algebra der Logik, insbesondere zum Entschei dungs-problem. Math. Ann. 86, 163–229 (1922).
2. Burks, A. W., and Wright, J. B., Theory of Logical Nets. Proc. IRE, 41, 1357–1365 (1953).
3. Church, Alonzo, Application of Recursive Arithmetic to the Problem of Circuit Synthesis, Proceedings of the Cornell Logic Conference, Cornell University, 1957. Also see “Application of Recursive Arithmetic in the Theory of Computing and Automata”, Notes for a summer course, The University of Michigan, 1959.
4. Copi, I. M., Elgot, C. C., and Wright, J. B., Realization of Events by Logical Nets. Journal Ass. Comp. Mach. 5, pp. 181–196 (1958).
5. Gödel, Kurt, On undecidable propositions of formal mathematical systems. Notes by S. C. Kleene and Barkley Rosser on lectures at the Institute for Advanced Study, 1934. Mimeographed, Princeton, N. J., 30 pp.