1. Barton N., R.Lien, Lunde J. (1974() - Rock Mechanics and Rock Engineering, Springer-Verlag, 6(4):189-236
2. Bieniawski Z.T. (1973) Engineering Classification of Jointed Rock Masses.Trans. S.Afr. Inst Civ. Eng. 15 pp.335-344
3. Bieniawski Z.T. (1976) Rock Mass Classification in Rock Engineering. Proc. Symp. Expl. Rock Eng. Johannesburg. Balkema Vol 1 pp.97-106 Bieniawski Z.T. (1984) Rock Mechanics Design in Mining and Tunnelling A.A. Balkema Rotterdam pp.97-133
4. Bieniawski Z.T. (1989) Engineering Rock Mass Classification. J.Wiley and Sons . N.
5. Hendrom A.J., Patton F.D. (1985) – TH Vajont slide, a geotechnical analysis based on new geological observations of the failure surface.