Z. Kołakowski and M. Królak, “Interactive Elastic Buckling of Thin-Walled Closed Orthotropic Beam-Columns”, Eng. Trans., vol. 43, no. 4, pp. 571–590, Dec. 1995, Accessed: Jan. 17, 2026. [Online]. Available: http://et.ippt.gov.pl/index.php/et/article/view/1518