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. 61 (Jun. 2015), 13-22. DOI:https://doi.org/10.20535/RADAP.2015.61.13-22.