1. Standard method of test for unconfined compressive strength of rock core specimens;ASTM;ASTM Book of Standards,1971
2. Engineering classification of jointed rock masses;Bieniawski;Trans. S. Afr. Inst. Civil Eng.,1973
3. Estimating the strength of rock materials;Bieniawski;J. S. Afr. Inst. Min. Metall.,1974
4. The point-load strength test;Broch;Int. J. Rock Mech. Min. Sci.,1972
5. Prediction of compressive strength of rock from other rock properties;D'Andrea;U.S. Bur. Mines Rep. Invest.,1965