The study of coal tectonic disturbance using multifractal analysis of coal specimen images obtained by means of scanning electron microscopyOlga Malinnikova, Dmitry Uchaev, Denis Uchaev and Vasiliy MalinnikovE3S Web Conf., 129 (2019) 01017DOI: https://doi.org/10.1051/e3sconf/201912901017