Ustych, S., A. Rovt, i S. Piasetska-Ustych. „A System Approach to Quantify Development of Modern Transborder Processes”. TRANSBORDER ECONOMICS. International Journal on Transborder Economics, Finance, Politics and Statistics., t. 1, nr 2, listopad 2023, s. 117-26, https://journals.ur.edu.pl/te/article/view/8611.