Godoli, G. “Numeri Caratteristici Dei Flocculi d’idrogeno E Di Calcio E Dei Filamenti d’idrogeno Per l’anno 1957”. Annals of Geophysics 10, no. 3-4 (November 25, 1957): 235–239. Accessed December 9, 2021. https://www.annalsofgeophysics.eu/index.php/annals/article/view/5913.