1. Rock Defects and Loads on Tunnel Support. Rock Tunnelling with Steel Supports;Terzaghi,1946
2. Gebirgsklassifizierung für den stollenbau;Lauffer;Geol Bauwes,1958
3. Zum der seitigen stand der gebirsklassifizierung in stollen-und tunnelbau;Pacher;Proc. XXII Geomech. Colloq, Salzburg.,1974
4. Design of Surface and Near Surface Construction in Rock;Deer,1967
5. Ground support prediction model(RSR concept);Wickham,1972