1. Cain, J. and Damnjanovic, Z.: 1991, ‘On the Weak Kleene Scheme in Kripke’s Theory of Truth’, Journal of Symbolic Logic, 56(4), 1452–1468.
2. Carnap, R.: 1936, ‘Testability and Meaning’, Philosophy of Science, 3, 420–471. Cleave, J. P.: 1973/74, ‘An Account of Entailment Based on Classical Semantics’, Analysis, 34, 118–122.
3. Czermak, J. and Weingartner, P.: 1983, ‘Criteria for Distinguishing Logically Necessary Proposition’, in: P. Weingartner and J. Czermak (Eds.), Epistemology and Philosophy of Science. Proceedings of the 7th International Wittgenstein Symposium (Kirchberg, 1982), Vienna: Hölder-Pichler-Tempsky, pp. 48–51.
4. Dalla Chiara, M. L.: 1981, ‘Logical Foundations of Quantum Mechanics’, in: E. Agazzi (Ed.), Modern Logic - A Survey, Dordrecht: Reidel, pp. 331–351.
5. Dalla Chiara, M. L.: 1991, ‘Epistemic Logic - Without Logical Omniscience’, in: G. Schurz and G. Dorn (Eds.), pp. 87–95.