1. Anderson, A. R. and N. D. Belnap, Jr.: 1975,Entailment: The Logic of Relevance and Necessity, Princeton University Press, Princeton.
2. Barwise, J. and J. Perry: 1983,Situations and Attitudes, MIT Press, Cambridge.
3. Bennett, J.: 1982, ?Even if?,Linguistics and Philosophy 5, 403?18.
4. Brame, M. D. S.: 1979, ?On Some Claims about If-Then?,Linguistics and Philosophy 3. 35?48.
5. Fauconnier, G.: 1975, ?Pragmatic Scales and Logical Structure?,Linguistic Inquiry 6, 353?75.