Sidekerskienė, Tatjana, and Jonas Rimas. “Analytical Investigation of the Control Sysytem With Delays”. Lietuvos matematikos rinkinys 47, no. spec. (June 15, 2021): 473–478. Accessed October 28, 2025. https://test.zurnalai.vu.lt/LMR/article/view/24247.