2Kohata Y, Wang L, Tatsuoka F, et al. Inherent and induced anisotropy of sedimentary soft rock[A]. In: Proc. of the 10^th Asian Regional Conf.on SMFE[C]. Beijing: [s. n.], 1995, 1: 33-36.
3Chong K P. Mechanical Characterization of Oil Shale[M]. New York:Elservier, 1984, 165-288.