DINH , V.C., NGUYEN , A.T., TRAN , V.T., NGUYEN , T.H.N. i DUONG , D.H. 2021. Applying Artificial Pillar to Replace the Coal Pillar Protecting Roadway to Increase Production Efficiency and Sustainable Development in the Vietnamese Coal Industry. Inżynieria Mineralna. 1, 2 (grudz. 2021). DOI:https://doi.org/10.29227/IM-2021-02-56.