GILBERT, F. The effect of arbitrarily small rigidity on the free oscillations of the Earth. Annals of Geophysics, [S. l.], v. 40, n. 5, 1997. DOI: 10.4401/ag-3857. Disponível em: https://www.annalsofgeophysics.eu/index.php/annals/article/view/3857. Acesso em: 21 jan. 2022.