1. Sadovsky, М.А., Natural Lumpiness of Rock, DAN SSSR, 1979, vol. 247, no. 4, pp. 829–832.
2. Kurlenya, М.V., Oparin, V.N., and Vostrikov, V.I., On the Formation of Elastic Wave Packages under Impulsive Excitation of Block Media. Pendulum Waves of $$U_{\mu}$$ Type, DAN SSSR, 1993, vol. 333, no. 4, pp. 3–13.
3. Kurlenya, М.V., Oparin, V.N., and Vostrikov, V.I., Pendulum-Type Waves. Part II: Experimental Methods and Main Results of Physical Modeling, J. Min. Sci., 1996, vol. 32, no. 4, pp. 245–273.
4. Kurlenya, М.V., Oparin, V.N., and Vostrikov, V.I., Pendulum-Type Waves. Part III: Data of On-Site Observations, J. Min. Sci., 1996, vol. 32, no. 5, pp. 341–361.
5. Oparin, V.N., Adushkin, V.V., Kiryaeva, Т.А., Potapov, V.P., Cherepov, А.А., Tyukhrin, V.G., and Glumov, А.V., Effect of Pendulum Waves from Earthquakes on Gas-Dynamic Behavior of Coal Seams in Kuzbass, J. Min. Sci., 2018, vol. 54, no. 1, pp. 1–12.