Sumaruk, Yu.P., and T.P. Sumaruk. “Dynamics of Temporal Changes of Geomagnetic Field Secular Variations”. Geofizicheskiy Zhurnal 38, no. 6 (December 1, 2016): 152–159. Accessed April 20, 2024. https://journals.uran.ua/geofizicheskiy/article/view/91884.