Sorokin, V. M., Fedorov, E. N., Yu. Schekotov, A., Molchanov, O. A., & Hayakawa, M. (2004). Depression of the ULF geomagnetic pulsation related to ionospheric irregularities. Annals of Geophysics, 47(1). https://doi.org/10.4401/ag-3271