1. Cheng Y P, Yu Q X, Yuan L, Li P, Liu Y Q, Tong Y F, 2004. Experimental research of safe and high-efficient exploitation of coal and pressure relief gas in long distance. Journal of China University of Mining & Technology, 33(2): 132–136.
2. Liu Z G, Yuan L, Dai G G, Shi B M, Lu P, Tu M, Cai F, 2004. Study on the characteristics of the gob roof cracks in stopes and its application in gas drainage. Journal of Anhui University of Science and Technology (Natural Science), 24(4): 10–15.
3. Yuan L, 2003. Research on gas drainage technology for seam group with complicated and difficult conditions. Coal Science and Technology, 31(11): 1–4.
4. Yuan L, 2004a. stability classification of coal roads in Huainan mining area and engineering countermeasures. Chinese Journal of Rock Mechanics and Engineering, 23(Z2): 4 790–4 794.
5. Yuan L, 2004b. Theory and technology on gas extraction for soft and low permeability seam group. Beijing: China Coal Industry Publishing House.