Jianguang Niu, Chunyan Gao, Dongyang Geng, Yongqiang Shi, Xiufeng Liang,. 2021. “Experimental Study on Slag Discharge of Sandstone in Small-Angle Reverse Drilling and Reaming”. Forest Chemicals Review, December, 974-88. http://forestchemicalsreview.com/index.php/JFCR/article/view/260.