Firstov, P. P., V. S. Yakovleva, V. A. Shirokov, and O. P. Malysheva. 2007. “The Nexus of Soil Radon and Hydrogen Dynamics and Seismicity of the Northern Flank of the Kuril-Kamchatka Subduction Zone”. Annals of Geophysics 50 (4). https://doi.org/10.4401/ag-3068.