Justification of the method of determination of the border overburden ratioSerhii Joukov, Serhii Lutsenko, Yulian Hryhoriev, Maxim Martyniuk and Volodymyr PeregudovE3S Web Conf., 166 (2020) 02005DOI: https://doi.org/10.1051/e3sconf/202016602005