Halanay, Andrei, and Carmen A. Safta. “Stability and Accuracy of Steady-State Motions in Loaded Copying System: Analytical Approach”. Computer Assisted Methods in Engineering and Science, vol. 6, no. 1, May 2023, pp. 107-13, https://cames3.ippt.pan.pl/index.php/cames/article/view/1328.