Source:
Proceedings of the International Scientific Conference of Daugavpils University / Daugavpils Universitates Starptautiskas Zinatniskas Konferences Materiali; 2021, Issue 63, p52-57, 6p
Source:
Proceedings of the International Scientific Conference of Daugavpils University / Daugavpils Universitates Starptautiskas Zinatniskas Konferences Materiali; 2020, Issue 62, p26-34, 9p