BOLLE, A.; SILLENI, S.; TIBERIO, A. REGISTRAZIONI IONOSFERICHE. Annals of Geophysics, [S. l.], v. 2, n. 3, p. 377–387, 1949. DOI: 10.4401/ag-5972. Disponível em: https://www.annalsofgeophysics.eu/index.php/annals/article/view/5972. Acesso em: 20 sep. 2021.