1. Austrian standards on B 2203-1 and-2 for underground works;NATM;Felsbau,2003
2. Engineering classification of jointed rock masses;Bieniawski;Civil Engineer in South Africa,1973
3. Engineering classification of rock masses for the design of tunnel support;Barton;Rock Mech.,1974
4. Ground behaviour and rock engineering tools for underground excavations;Palmstrom;Tunn. Undergr. Space Technol.,2007
5. In Support determinations based on geologic predictions;Wickham;N Am Rapid Excav & Tunnelling Conf Proc,1972