Contadakis, Michael E., Dimitrios N. Arabelos, Christos Pikridas, and Spyrous D. Spatalas. “Total Electron Content Variations over Southern Europe before and During the M 6.3 Abruzzo Earthquake of April 6, 2009”. Annals of Geophysics 55, no. 1 (April 24, 2012). Accessed June 12, 2026. https://www.annalsofgeophysics.eu/index.php/annals/article/view/5322.