1. Pillar extraction at the Doe run company, 1991–1998;Roberts,1998
2. The use of computer applications at BCL Limited in planning pillar extraction and the design of mining layouts;Von Kimmelmann,1984
3. Failure modes and pillar behaviour in the Zinkgruvan mine;Sjoberg,1992
4. Determination of the strength of hard-rock mine pillars;Lunder;Cim Bull,1997
5. Determining pillar strength-from pillar failure observation;Krauland;E&MJ-Eng Min J,1987