Dorgan, R.J., and G.Z. Voyiadjis. “Functional Forms of Hardening Internal State Variables in Modeling Elasto-Plastic Behavior”. Archives of Mechanics 59, no. 1 (February 28, 2007): 35–58. Accessed March 2, 2026. https://am.ippt.pan.pl/index.php/am/article/view/v59p35.