1. Engineering classification of rock masses for the design of tunnel support;Barton;Rock Mechanics,1974
2. Engineering Rock Mass Classification;Bieniawski,1989
3. DIPS Software (Data Interpretation Package Using Stereographic Projection);Diederichs,1989
4. Geo Slope International, 1999. Slope/W User's Manual. Calgary, Alberta, Canada, p. 160.
5. Rock Slope Engineering;Hoek,1981