1. Aristorenas, G. (1992): Time dependent behaviour of tunnels excavated in shale. Ph.D. Thesis, MIT, Cambridge, Ma.
2. Beck, A., Golta, A. (1972): Tunnelsanierungen der Schweiz, Bundesbahnen, Schweiz. Bauz. 90(36).
3. Bellwald, P. (1991): A contribution to the design of tunnels in argillaceous rocks. Ph.D. Thesis, MIT, Cambridge, Ma.
4. Bellwald, P., Einstein, H. H. (1987): Elasto-plastic constitutive model. Proc., 6th Int. Congress ISRM, Montreal.
5. Einstein, H. H. (1979): Tunneling in swelling rocks. Underground Space 4 (1).