On an Optimal Quantified Propositional Proof System and a Complete Language for NP cap co-NP. - Zenon Sadowski (FCT, 1997)

On an Optimal Deterministic Algorithm for SAT. - Zenon Sadowski (CSL, 1998)

On a P-optimal Proof System for the Set of All Satisfiable Boolean Formulas (SAT). - Zenon Sadowski (MCU, 2001)

On an optimal propositional proof system and the structure of easy subsets of TAUT. - Zenon Sadowski (Theor. Comput. Sci., 2002)

On a D-N-optimal acceptor for TAUT - Zenon Sadowski (Electron. Colloquium Comput. Complex., 2005)

Optimal Proof Systems, Optimal Acceptors and Recursive Presentability. - Zenon Sadowski (Fundam. Informaticae, 2007)

Optimal Proof Systems and Complete Languages. - Zenon Sadowski (Electron. Colloquium Comput. Complex., 2008)

Characterizing the Existence of Optimal Proof Systems and Complete Sets for Promise Classes. - Olaf Beyersdorff; Zenon Sadowski (Electron. Colloquium Comput. Complex., 2009)

Do there exist complete sets for promise classes? - Olaf Beyersdorff; Zenon Sadowski (Math. Log. Q., 2011)

Total Nondeterministic Turing Machines and a p-optimal Proof System for SAT. - Zenon Sadowski (CiE, 2017)