TİMOÇİN, Erdinç, and İbrahim ÜNAL. “Analysis of the Probable Signature of Mid-Latitude Electron Density Trough at the Ionospheric Critical Frequencies over Europe”. Annals of Geophysics 60, no. 3 (May 4, 2017): A0332. Accessed October 27, 2021. https://www.annalsofgeophysics.eu/index.php/annals/article/view/7065.