Fang, K., W. Huang, C. Song, and S. Hu. “Influence and Control Effect of Drawing Speed on Mining-Induced Fractures "O” Form Circle’s Fully Mechanized Surface”. Journal of Mines, Metals and Fuels, vol. 65, no. 9, Sept. 2017, pp. 503-8, doi:10.18311/jmmf/2017/26978.