1. Scale effect or sampling bias?;Barton,1990
2. Engineering classification of rock masses fro the design of rock support;Barton;Rock Mech.,1974
3. Modulus testing of rock at the Churchill falls underground powerhouse, Labrador;Benson,1970
4. Engineering classification of jointed rock masses;Bieniawski;Trans. S. African Instn. Civ. Engrs.,1973
5. Engineering Rock Mass Classifications;Bieniawski,1989