1. Engineering classification of rock masses for the design of tunnel supports;Barton;Rock Mechanics,1974
2. Bieniawski, Z.T., 1976. Rock mass classification in rock engineering. In: Proceedings of the Symposium on Exploration for Rock Engineering, Cape Town, Balkema, pp. 97–106.
3. Bieniawski, Z. T., 1989. Engineering Rock Mass Classifications. John Wiley and Sons, p. 237.
4. The use of the slip circle in the stability analysis of slopes;Bishop;Geotechnique,1955
5. Estimation of rock mass deformation modulus and strength of jointed hard rock masses using the GSI system;Cai;Int. J. Rock Mech. Min. Sci.,2004