Counting maximal distance-independent sets in grid graphs / Reinhardt Euler, Paweł OLEKSIK, Zdzisław SKUPIEŃ // Discussiones Mathematicae. Graph Theory ; ISSN 1234-3099. — 2013 vol. 33 no. 3, s. 531–557. — Bibliogr. s. 557, Abstr.

Sums of powered characteristic roots count distance-independent circular sets / Zdzisław SKUPIEŃ // Discussiones Mathematicae. Graph Theory ; ISSN 1234-3099. — 2013 vol. 33 no. 1, s. 217–229. — Bibliogr. s. 228–229, Abstr.. — tekst: http://web.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=7b477346-5193-4011-9722-f6f3bc229519%40sessionmgr12&vid=2&hid=14

Universal third parts of any complete 2-graph and none of $DK_{5}$ / Artur FORTUNA, Zdzisław SKUPIEŃ // Opuscula Mathematica ; ISSN 1232-9274. — Tytuł poprz.: Scientific Bulletins of Stanisław Staszic Academy of Mining and Metallurgy. Opuscula Mathematica. — 2013 vol. 33 no. 4, s. 685–696. — Bibliogr. s. 695–696, Abstr.