ZAGIRNYAK, Valentina; NEVZLIN, Boris; ZAHORULKO, Veronika. DETERMINATION OF THE CONDITIONS FOR THE EXISTENCE OF HIGHER-ORDER DIFFERENTIAL ELECTROMAGNETIC INVARIANTS. Journal of Energy Technology, [S. l.], v. 8, n. 2, p. 11–16, 2024. DOI: 10.18690/jet.8.2.11-16.2015. Disponível em: https://journals.um.si/index.php/jet/article/view/4395. Acesso em: 7 dec. 2025.