- On strong fragments of Peano arithmetic2015 | Faculty of Arts
- Infinite Natural Numbers: an Unwanted Phenomenon, or a Useful Concept?2011 | Faculty of Arts
- Not all Kripke models of HA are locally PA2022 | Faculty of Mathematics and Physics
- Where is the Gödel-Point hiding: Gentzen's Consistency Proof of 1936 and his Representation of Constructive Ordinals2014 | Faculty of Arts
- Quasi-Euclidean subrings of Q[x]2013 | Faculty of Mathematics and Physics
- The Intuitionistic Robinson Arithmetic(s)2015 | Faculty of Arts