1. The ultimate frictional resistance of rock discontinuities;Krahn;Int. J. Rock Mech. Min. Sci. & Geomech. Abstr.,1979
2. Initial and residual shear strength of hard rocks;Krsmanovic;Geotechnique,1967
3. The shear strength of rock joints in theory and practice;Barton;Rock Mechanics,1977
4. Very large span openings at shallow depth: Deformation magnitudes from jointed models and F.E. analysis;Barton,1979