1. A study of the strength of coal pillars;Salamon;J S Afr Inst Min Metall,1967
2. A re-assessment of coal-pillar design;Madden;J S Afr Inst Min Metall,1991
3. Stope-and-pillar design for elliot lake uranium mines;Hedley;Can Min Metall Bull,1972
4. Practical estimates of rock mass strength;Hoek;Int J Rock Mech Min Sci,1997
5. Failure modes and pillar behaviour in the Zinkgruvan mine;Sjoberg,1992