ZIEMELIS, J. Problems of Secondary Sources for Hybrid Ray Tracing and FEM Simulation. Elektronika ir Elektrotechnika, [S. l.], v. 47, n. 5, 2003. DOI: 10.5755/j02.eie.11269. Disponível em: https://eejournal.ktu.lt/index.php/elt/article/view/11269.. Acesso em: 5 may. 2026.