Ільясова, Ю., and О. Шарпан. “The Analysis of Linear Systems in the Field of Transformations at the Minimal Different Equations”. Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, no. 35, Feb. 2007, pp. 23-29, doi:10.20535/RADAP.2007.35.23-29.