Matzka, Jürgen, Nils Olsen, Cathrine Fox Maule, Lars William Pedersen, Alan M. Berarducci, and Susan Macmillan. “Geomagnetic Observations on Tristan Da Cunha, South Atlantic Ocean”. Annals of Geophysics 52, no. 1 (January 25, 2009): 97–105. Accessed April 26, 2024. https://www.annalsofgeophysics.eu/index.php/annals/article/view/4633.