Features and regularity of zonal changes in the physicomechanical characteristics of Zakhidnyi Donbas rocksTetiana Palamarchuk, Liliia Prokhorets, Mykola Bobro and Valerii TrypolskyiE3S Web Conf., 109 (2019) 00068DOI: https://doi.org/10.1051/e3sconf/201910900068