On the Scope of the Classical Deduction Theorem. - Witold A. Pogorzelski (J. Symb. Log., 1968)

Structural completeness of the first-order predicate calculus. - Witold A. Pogorzelski; Tadeusz Prucnal (Math. Log. Q., 1975)

Cn-Definitions of Propositional Connectives. - Witold A. Pogorzelski; Piotr Wojtylak (Stud Logica, 2001)

A Proof System for Classical Logic. - Witold A. Pogorzelski; Piotr Wojtylak (Stud Logica, 2005)