Гулька, Степан Степанович. 2019. “THE METHOD OF PART MIDDLING IN THE INTEGRAL- DIFFERENTIAL SYSTEMS WITH DOUBLE IMPULSIVE ACTION”. PRECARPATHIAN BULLETIN OF THE SHEVCHENKO SCIENTIFIC SOCIETY. Number, no. 1(5) (March):20-23. https://pvntsh.nung.edu.ua/index.php/number/article/view/306.