1. Barczak TM (1986) State of the art testing and analysis of mine roof support systems, Eastern coal mine geo-mechanics. In: Proceedings of Bureau of Mines Technology Transfer Seminar (Pittsburgh, PA, November 1986, US Department of Interior, Bureau of Mines), IC 9137
2. Barczak TM (1992) Examination of design and operation practices for longwall shields. US Department of Interior, Bureau of Mines, RI 9320
3. Barczak TM, Schwemmer DE (1988) Stiffness characteristics of longwall shields. US Department of Interior, Bureau of Mines, RI 9154
4. Itasca (2000) FLAC version 4.0 user’s manual. Itasca Consulting Group, Inc., Minneapolis, Minnesota, USA
5. Jaeger JC, Cook NGW (1979) Fundamentals of rock mechanics. Chapman and Hall, London