Independent Axiomatizability of Sets of Sentences. - Piotr Wojtylak (Ann. Pure Appl. Log., 1989)

Restricted Versions of the Compactness Theorem. - Adam Kolany; Piotr Wojtylak (Reports Math. Log., 1991)

On structural completeness of implicational logics. - Piotr Wojtylak (Stud Logica, 1991)

Finite Distributive Lattices as Sums of Boolean Algebras. - Jerzy Kotas; Piotr Wojtylak (Reports Math. Log., 1995)

The Uniqueness of the Decomposition of Distributive Lattices into Sums of Boolean Lattices. - Joanna Grygiel; Piotr Wojtylak (Reports Math. Log., 1997)

On the Problem of R. E. Tax. - Piotr Wojtylak; Andrzej Wronski (Reports Math. Log., 2001)

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

On a Problem of H. Friedman and its Solution by T. Prucnal. - Piotr Wojtylak (Reports Math. Log., 2004)

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

Generalizing proofs in monadic languages. - Matthias Baaz; Piotr Wojtylak (Ann. Pure Appl. Log., 2008)

An algorithm for the number of path homomorphisms. - Srichan Arworn; Piotr Wojtylak (Discret. Math., 2009)

Projective Unifiers in Modal Logics. - Wojciech Dzik; Piotr Wojtylak (UNIF, 2011)

Projective unification in modal logic. - Wojciech Dzik; Piotr Wojtylak (Log. J. IGPL, 2012)

Almost structurally complete infinitary consequence operations extending S4.3. - Wojciech Dzik; Piotr Wojtylak (Log. J. IGPL, 2015)

Unification in predicate logic. - Wojciech Dzik; Piotr Wojtylak (UNIF, 2016)

Modal Consequence Relations Extending S4.3: An Application of Projective Unification. - Wojciech Dzik; Piotr Wojtylak (Notre Dame J. Formal Log., 2016)

Unification in first-order transitive modal logic. - Wojciech Dzik; Piotr Wojtylak (Log. J. IGPL, 2019)

Unification in superintuitionistic Predicate Logics and its Applications. - Wojciech Dzik; Piotr Wojtylak (Rev. Symb. Log., 2019)

Finitary unification in locally tabular modal logics characterized. - Wojciech Dzik; Slawomir Kost; Piotr Wojtylak (Ann. Pure Appl. Log., 2022)

Unification types and union splittings in intermediate logics. - Wojciech Dzik; Slawomir Kost; Piotr Wojtylak (Ann. Pure Appl. Log., 2025)