1. Buchholz, W., Schütte, K.: Proof theory of impredicative subsystems of analysis. Napoli: Bibliopolis 1988
2. Girard, J.-Y.: 79-1 logic. Ann. Math. Logic21, 75?271 (1981)
3. Girard, J.-Y., Ressayre, J.P.: Elements de logique? n 1. Proc. Symp. Pure Math.42, 339?445 (1985)
4. Schwichtenberg, H.: Proof of theory: some applications of cut elimination. In: Barwise, J. (ed.) Handbook of Mathematical Logic. Amsterdam: North-Holland 1977
5. Takeuti, G.: Proof theory. Amsterdam: North-Holland 1975