Here there are some articles with preprints of the most of them.
These versions may be different from the final, published versions.

13. A modal logic of a truth definition for finite models
, abstract, pdf
(with Marek Czarnecki), preprint.

12. Lower bounds for the unprovability of Herbrand consistency in weak arithmetics, abstract, pdf
(with Zofia Adamowicz), accepted in Fundamenta Mathematicae.

11. On a question of Andreas Weiermann, abstract, pdf, published version
(with Henryk Kotlarski), Mathematical Logic Quaterly 55(2009), pp. 201-211.

10. On the  second order intuitionistic propositional logic without a universal quantifier, abstract, pdf, published version,
Journal of Symbolic Logic 74(2009), pp.157-167.

9. Undecidability and concatenation, abstract, pdf, published version
(with Andrzej Grzegorczyk), 
in Andrzej Mostowski and Foundational Studies,

ed. W. Marek, A. Ehrenfeucht, M. Srebrny, IOS Press, Amsterdam, 2008.

8. Finite arithmetics, abstract, pdf, published version
(with Michał Krynicki and Marcin Mostowski),
Fundamenta Informaticae 81(2007), pp. 183-202.

7. The Intended Model of Arithmetic.
An Argument from Tennenbaum's Theorem
, abstract, pdf
(with Paula Quinon), in Computation and Logic in the Real World, CiE 2007,
Local Proceedings, ed. S.B. Cooper, B. Loewe i A. Sorbi, 2007.

6. Coprimality in finite modelsabstract,
pdf, published version
(with Marcin Mostowski), Proc. of CSL 2005,
Lecture Notes in Computer Science, vol. 3634,
Springer, pp. 263-275.

5. FM-representability and beyond, abstract,
pdf, published version
(with Marcin Mostowski), Proc. of CiE 2005,
Lecture Notes in Computer Science, vol. 3526,
Springer, pp. 358-367.

4. Theories of arithmetics in finite models, abstract,
pdf, published version
(with Michał Krynicki), Journal of Symbolic Logic, 70(2005), pp. 1-28.

3. Degrees of logics with Henkin Quantifiers
in poor vocabularies
, abstract,
pdf, published version
(with  Marcin Mostowski), Archive for Mathematical Logic, 43(2004), pp. 691-702.

2. On Spectra of formulae with Henkin Quantifiers
(with  Joanna Golińska-Pilarek), Philosophical
Dimensions of Logic and Science, Proc. of LMPhSc 1999 in Cracow,
ed. A. Rojszczak, J. Cachro, G. Kurczewski, Kluwer, 2003, pp. 29-45.

1. Ph.D. thesis
Arithmetics in finite but potentially infinite worldsabstract, short summary, pdf
Warsaw University, 2005.