Шаповалов, Ю. І., Мандзій, Б. А. and Бачик, Д. Р. (2015) “About the accuracy of assessment of stability of linear periodically time-variable circuits by the frequency symbolic method”, Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, 0(61), pp. 13-22. doi: 10.20535/RADAP.2015.61.13-22.