Hejda, Pavel, Josef Horáček, and Tomáš Bayer. “Secular Variation on the Territory of the Czech Republic and Reduction of the Magnetic Survey to the Epoch 2010.5”. Annals of Geophysics 55, no. 6 (March 7, 2013). Accessed April 25, 2024. https://www.annalsofgeophysics.eu/index.php/annals/article/view/5445.