DUĆ-FAJFER, Olena. Vstup. Rocznik Ruskiej Bursy, [S. l.], v. 13, p. 9–12, 2017. DOI: 10.12797/RRB.13.2017.13.01. Disponível em: https://journals.akademicka.pl/rrb/article/view/541. Acesso em: 1 jun. 2025.