1. Y. Shapovalov, Symbolic analysis of linear electrical circuits in the frequency domain. Fixed and variable parameters (LPNU, Lviv, 2014).
2. Y. Shapovalov, B. Mandziy, S. Mankovsky, "The peculiarities of analysis of linear parametric circuit performed by frequency-symbolic method," Prz. Elektrotechniczny, v.86, n.1, p.158 (2010). URI: https://www.infona.pl/resource/bwmeta1.element.baztech-article-BPOB-0026-0001/tab/summary.
3. Y. Shapovalov, D. Bachyk, I. Shapovalov, "Matrix equation of L.A. Zadeh and its application to the analysis of the LPTV circuits," in 19th International Conference Computational Problems of Electrical Engineering (IEEE, 2018). DOI: https://doi.org/10.1109/CPEE.2018.8506766.
4. Y. Shapovalov, D. Bachyk, K. Detsyk, "Multivariate modelling of the LPTV circuits in the MAOPCs software environment," Prz. Elektrotechniczny, v.98, n.7, p.158 (2022). URI: http://pe.org.pl/abstract_pl.
5. B. Ho Eom, P. K. Day, H. G. LeDuc, J. Zmuidzinas, "A wideband, low-noise superconducting amplifier with high dynamic range," Nat. Phys., v.8, n.8, p.623 (2012). DOI: https://doi.org/10.1038/nphys2356.