Extremum degree sets of irregular oriented graphs and pseudodigraphs. - Zyta Dziechcinska-Halamoda; Zofia Majcher; Jerzy Michael; Zdzislaw Skupien (Discuss. Math. Graph Theory, 2006)

A Sokoban-type game and arc deletion within irregular digraphs of all sizes. - Zyta Dziechcinska-Halamoda; Zofia Majcher; Jerzy Michael; Zdzislaw Skupien (Discuss. Math. Graph Theory, 2007)

Extremal irregular digraphs. - Zyta Dziechcinska-Halamoda; Joanna Górska; Zofia Majcher; Jerzy Michael; Zdzislaw Skupien (Discuss. Math. Graph Theory, 2018)