AVIATION RADIO DIRECTION FINDERS AND NON-DIRECTIONAL BEACONS: PRINCIPLES OF OPERATION AND THEIR IMPORTANCE IN AVIATION. Eureka Journal of Geoscience, Materials & Resource Engineering, [S. l.], v. 2, n. 4, p. 18–26, 2026. Disponível em: https://eurekaoa.com/index.php/9/article/view/792. Acesso em: 19 may. 2026.