On the empirical linkages between stock prices and trading activity on the German stock market / Roland Mestel, Henryk GURGUL, Paweł Majdosz // W: Operations research proceedings 2004 : selected papers of the annual conference of the German Operations Research Society (GOR) ; Jointly organized with the Netherlands Society for Operations Research (NGB) : Tilburg, September 1–3, 2004 / eds. Hein Fleuren, Dick den Hertog, Peter Kort. — [Heidelberg] : Springer, [2004]. — DOI: 10.1007/3-540-27679-3. — ISBN: 978-3-540-24274-1 ; e-ISBN: 978-3-540-27679-1. — S. 288–296. — Bibliogr. s. 295–296, Abstr.. — tekst: https://link-1springer-1com-1000048go003e.wbg2.bg.agh.edu.pl/content/pdf/10.1007%2F3-540-27679-3_36.pdf

Trading volume and stock prices on the Austrian stock market / Roland Mestel, Henryk GURGUL, Paweł Majdosz // W: Mathematical methods in economics 2004 : proceedings of the 22\textsuperscript{nd} international conference : 15–17 September 2004, Brno / Czech Society for Operations Research, Czech Econometric Society, Masaryk University Brno. Faculty of Economics and Administration. — Czech Republic : [s. n.], [2004]. — S. 195–200. — Bibliogr. s. 200, Abstr.

Zum Informationsgehalt des Handelsvolumens für die Preisentwicklung gehandelter Ansprüche — [Information content of trading volume for price building of equities] / Roland Mestel, Henryk GURGUL // W: Betriebswirtschaftslehre und gesellschaftliche Verantwortung : 66. Wissenschaftliche Jahrestagung : [Graz], 1. bis 4. Juni 2004 / Uni Graz. — Austria. : s. n, [2004]. — S. 53–56