1. American Society for Testing and Materials. Standard test method for unconfined compressive strength of intact rock core specimens. Soil and Rock, Building Stones: Annual Book of ASTM Standards 4.08. Philadelphia, Pennsylvania: ASTM, 1984.
2. ISRM Suggested Methods. In: Brown ET, editor. Rock characterisation testing and monitoring. Oxford: Pergamon Press, 1981.
3. Kahraman S. The development of a model to obtain suitable drilling and blasting conditions in open pit mines and quarries. Ph.D. thesis, Istanbul Technical University, 1997 [in Turkish].
4. Eskikaya S, Bilgin N. Research into drillability and optimum drill bit usage for rotary drills in Turkish Coal Enterprises. Final Report, vol. 2, Istanbul Technical University, 1993.
5. Drillability studies on the rotary blashole drilling of lignite overburden series;Karpuz;Int J Surface Min Rec,1990