OSTROWSKI, Norbert. The Etymologies of Perkūnas and aitivaras. Vilnius University Open Series, [S. l.], n. 1, p. 39–43, 2018. DOI: 10.15388/Proceedings.2018.3. Disponível em: https://test.zurnalai.vu.lt/open-series/article/view/12986. Acesso em: 26 oct. 2025.