1. Mechanism of Brittle Fracture of Rock;Bieniawski,1967
2. A critical review of the present state of scientific knowledge related to the strength of coal pillars;Denkhaus;J.S. African Inst. Mining Met.,1962
3. Stress analysis applied to mining problems, 2. Stress analysis applied to multiple openings in pillars;Duvall;Rept. Invest. U.S. Bur. Mines, RI4387,1948
4. The compressive strength of coal;Evans;Colliery Eng.,1961
5. The compressive strength of coal;Evans;Colliery Eng.,1961