Lower bounds for a proof system with an exponential speed-up over constant-depth Frege systems and over polynomial calculus

Krajíček, J. Lower bounds for a proof system with an exponential speed-up over constant-depth Frege systems and over polynomial calculus. In: RŮŽIČKA, P. R., ed. Mathematical Foundations of Computer Science. Berlin: SpringerVerlag, 1997, s. 85-90. Lecture Notes in Computer Science, 1295.