PREPRINTS
1. Ab5-star Abelian groups
(1987).
2. Extending Abelian groups
(1999).
3. Dual Zassenhaus Lemma
(2003).
3. Schreier Lattices
(2005).
4. Determination of
torsion-free Abelian groups by their direct powers (2006).
5. Intersections of principal right ideals in
regular rings are principal: a direct proof (2008).
6. Abelian groups with
dual endomorphism ring (2009).
7. Abelian groups with
unit-regular endomorphism ring (2009).
8. Extensions by factor sets for some lattices
(2010).
9. Sections and retractions in the category Grp
(2010).
10. On unit-regular rings
(2010).
11. Abelian groups with reduced endomorphism ring
(2014).
12. Additive groups of rings with identity
(2014).
13. Regular Abelian groups and elements
(2016, revised 2018).
14. Uniquely fine 2 × 2 integral matrices
(2016).
15. Similarity and class numbers. Clean 2x2 integral matrices
(2017).
16. Exceptional units in matrix rings
(2018).
17. Exchange 2 x 2 matrices over principal ideal domains: a characterization
(2019).
18. Examples of equivalent matrices that are not similar
(2021).
19. Similarity for zero-square matrices
(2021).
20. A nil-clean matrix example improved by computer
(2021).
21. A 3 × 3 nilpotent matris of index 3 which has unit
Stable range one
(2021).
22. On products of stable range one elements
(2022).
23. A zero determinant 2 × 2 matrix which has not
stable range one
(2023).
24. On the recognition of upper triangular matrix rings
(2023).
25. Unipotent-regular matrices and rings
(2023).
26. An idempotent not conjugate with its complementary idempotent
(2024).
27. Negative nil-clean rings
(2024).