Shuman, V.N., V. P. Kobolev, V. I. Starostenko, I. B. Burkinskiy, N. P. Loyko, I. G. Zakharov, and D. A. Yatsiuta. 2012. “A Method of Analysis of Spontaneous Electromagnetic Emission of the Earth: Physical Backgrounds, Elements of Theory, Field Experiment”. Geofizicheskiy Zhurnal 34 (4):40-61. https://doi.org/10.24028/gzh.0203-3100.v34i4.2012.116749.