1. [Baaz, M. and Leitsch, A., 1994]On Skolemization and Proof Complexity. Fundamenta Informaticae 20(4), pages 353–379.
2. [Baaz, M. and Leitsch, A., 1999]Cut normal forms and proof complexity. Ann. Pure Appl. Logic 97(1-3), pages 127–177.
3. [Baaz, M. and Pudlák, P., 1993]Kreisel’s conjecture for L.1. In P. Clote and J. Krajíček, editors, Arithmetic, Proof Theory and Computational Complexity, pages 29–59. Oxford University Press, 1993. With a postscript by G. Kreisel.
4. [Leitsch, A., 1997]The Resolution Calculus. Springer-Verlag, Berlin, Heidelberg, New York.
5. [Takeuti, G., 1980]Proof Theory. North-Holland, Amsterdam, 2nd edition.