MURRI, A., R. FUSARI, and C. SCUTERINI. “The Mutual Relations Between Solar Activity, Thunderstorms and Vertical Gradients of Electro Atmospheric Potential”. Annals of Geophysics 27, no. 1-2 (November 25, 1974): 37–45. Accessed March 28, 2024. https://www.annalsofgeophysics.eu/index.php/annals/article/view/4912.