Application of impedance spectrossopy for determination of cracking of gas-saturated coal beds in the real conditions of backwall - L. I. Stefanovich; V. V. Sobolev; A. N. Molchanov; N. V. Bilan; A. A. Kamchatnyj; E. A. Pronskij (Fyzyko-tekhnycheskye problemy hornoho proyzvodstva, 2017)