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

Axiomatization of the Logic Determined by the System of Natural Numbers with Identity. - Beata Bugajska-Jaszczolt; Tadeusz Prucnal (Reports Math. Log., 1994)

On the Logic Determined by some Finite Relational Systems. - Tadeusz Prucnal (Reports Math. Log., 1998)