Study on proportioning of similar materials for overburden rock in underground gasification model experimentLin Xin, Limin Han, Mingyu An, Jian Li, Chao Li, Min Xu, Mingze Feng and Kaixuan LiE3S Web Conf., 303 (2021) 01057DOI: https://doi.org/10.1051/e3sconf/202130301057