1. Bi J, Su X (2001) The relation between cleat frequency and coal rank. J China Coal Soc 26(4):346–349 (in Chinese)
2. Cao S, Liu Y, Zhang L (2007) Study on characteristics of acoustic emission in outburst coal. Chin J Rock Mech Eng 26(S1):2794–2799 (in Chinese)
3. Chen J, Qin Y, Song Q et al (2003) Coupling relationship between direction of coalbed cleat and methane drainage effect and its prediction model. J China Univ Min Technol 32(3):223–226 (in Chinese)
4. Chen H, Cheng Y et al (2014) Permeability distribution characteristics of protected coal seams during unloading of the coal body. Int J Rock Mech Min Sci 71:105–116
5. Feng X, Zhang N, Zheng X et al (2015) Strength restoration of cracked sandstone and coal under a uniaxial compression test and correlated damage source location based on acoustic emissions. PLoS One 12:1–20