Variation of Radio Refractivity with Height above Ground. Elektronika ir Elektrotechnika, [S. l.], v. 111, n. 5, p. 23–26, 2011. DOI: 10.5755/j01.eee.111.5.349. Disponível em: https://eejournal.ktu.lt/index.php/elt/article/view/349.. Acesso em: 5 dec. 2025.