Shakhovska, Natalya     The identification of the operators systems images using the method of the phase portrait [Текст] / Natalya Shakhovska, Lilia Nych, Roman Kaminskyj // Advances in intelligent systems and computing : selected papers from the intern. conf. on computer science and inform. technologies, CSIT 2016, Sept. 6-10 Lviv, Ukraine / ed. Natalya Shakhovska. — 2016. — P. 241-254.