VAN ZELE, M. A.; OTTO, O. Quiet solar geomagnetic variations at observatories in symmetrical latitudes during a minimum of solar activity. Geoacta, [S. l.], v. 20, p. 27–35, 1993. Disponível em: https://revistas.unlp.edu.ar/geoacta/article/view/13700. Acesso em: 18 jul. 2024.