BORGHI, D. C. GENERAL SOLUTIONS OF SECOND ORDER LINEAR HOMOGENEOUS DIFFERENTIAL EQUATIONS. Annals of Geophysics, [S. l.], v. 8, n. 2, p. 167–180, 1955. DOI: 10.4401/ag-5670. Disponível em: https://www.annalsofgeophysics.eu/index.php/annals/article/view/5670. Acesso em: 27 nov. 2021.