Palano, Mimmo, Massimo Rossi, Flavio Cannavò, Valentina Bruno, Marco Aloisi, Daniele Pellegrino, Mario Pulvirenti, Giuseppe Siligato, and Mario Mattia. “Etn@ref: A Geodetic Reference Frame for Mt. Etna GPS Networks”. Annals of Geophysics 53, no. 4 (December 21, 2010): 49–57. Accessed October 1, 2022. https://www.annalsofgeophysics.eu/index.php/annals/article/view/4879.