1. [1] Addison, J. W., L. Henkin, and A. Tarski, editors, The Theory of Models. Proceedings of the 1963 International Symposium at Berkeley, North-Holland Publishing Co., Amsterdam, 1965.
2. [2] Barwise, J., and S. Feferman, editors, Model-theoretic Logics, Perspectives in Mathematical Logic. Springer-Verlag, New York, 1985.
3. [3] Barwise, J., "Back and forth through infinitary logic", pp. 5--34 in Studies in Model Theory, vol. 8 of MAA Studies in Mathematics, The Mathematical Association of America, Buffalo, 1973.
4. [4] Barwise, K. J., "Absolute logics and $L_\infty \omega $", Annals of Pure and Applied Logic, vol. 4 (1972), pp. 309--40.
5. [5] Bonnay, D., Qu'est-ce qu'une constante logique?, Ph.D. Dissertation, Université Paris I, 2006.