1. 1) Oucterlony, F. (1986),“ A core bend specimen with chevron notch for fracture toughness measurements”, Proceedings of the 27th U.S. Symposium of Rock Mechanics, Tuscaloosa, June.
2. 2) Whittaker, B.N., Singh, R.N. and Sun, G. (1992), Rock Fracture Mechanics: Principles, Design, and Applications (Developments in Geotechnical Engineering vol.71), Elsevier, Amsterdam, Netherlands.
3. 3) Barker, L.M. (1977),“ A simplified method for measuring plane strain fracture toughness”, Eng. Fract. Mech., 9, 361-369.
4. 4) Ouchterlony, F. (1980), “A new core specimen for the fracture toughness testing of rock”, Swedish Detonic Research Foundation Report No. DS 17, Stockholm, Sweden.
5. 5) Bush, A. J. (1976), “Experimentally determined stress intensity factor for single-edge crack round bars loaded in bending”, Expl. Mech., 16, 249-257.