КУЗИШИН, Іванна Ярославівна. PERIODICITY OF SOLUTIONS TO LINEAR SYSTEMS OF ORDINARY DIFFERENTIAL EQUATIONS WITH PERTUBATION. PRECARPATHIAN BULLETIN OF THE SHEVCHENKO SCIENTIFIC SOCIETY. Number, [S. l.], n. 1(29), p. 90–94, 2019. Disponível em: https://pvntsh.nung.edu.ua/index.php/number/article/view/143. Acesso em: 6 dec. 2025.