1.
Belehaki A, Moraitis G, Tsagouri I. On the derivation of an hourly local index to define the normal ionosphere. Ann. Geophys. [Internet]. 2000 Dec. 25 [cited 2026 Apr. 28];43(1). Available from: https://www.annalsofgeophysics.eu/index.php/annals/article/view/3629