“Symmetric Forms of the Equations of Heat Transport in a Rigid Conductor of Heat With Internal State Variables. I. Analysis of the Model and Thermodynamic Restrictions via the ‘main Dependency Relation’”. Archives of Mechanics - Test, vol. 50, no. 2, Jan. 1998, pp. 143-7, https://am3.ippt.pan.pl/index.php/am/article/view/v50p143.