1. A. V. Kuptsov, I.A. Larionov, and B. M. Shevtsov, Vulkanol. Seismol., No. 5, 49–59 (2005).
2. G. I. Dolgikh, A. V. Kuptsov, I. A. Larionov, et al., Dokl. Earth Sci. 413, 281–285 (2007).
3. B. M. Shevtsov, Yu. V. Marapulets, and A. O. Shcherbina, Dokl. Earth Sci. 430, 67–70 (2010).
4. A. Ya. Sidorin, Earthquake Precursors (Nauka, Moscow, 1992) [in Russian].
5. O. P. Rulenko, Vulkanologiya i Seismologiya, No. 4, 57–68 (2000).