1. D. Heliot, A. Etchecopar and P. Cheung, in Proceedings of the Rock at Great Depth Symposium, Pau, France (1989) 1471?1478.
2. C. Barton and M. Zoback, Journal of Geophysical Research 99 (1994) 9373?9390.
3. V.M. Maury and J.M Sauzay, in Proceedings of the Rock at Great Depth Symposium, Pau, France (1989) 871?876.
4. V.M. Maury, in Proceedings of the Eurock 94 Symposium, Delft, The Netherlands (1994) 175?182.
5. C. Atkinson and M. Thiercelin, International Journal of Fracture 59 (1993) 23?40.