1. The squeezing potential of rocks around tunnels; theory and prediction;Aydan;Rock Mech. Rock Eng.,1993
2. Aygar, E., 1999. A critical approach to the New Austrian Tunneling Method in Bolu tunnels, Hacettepe University, Graduate School, Master Thesis, 267 pp. (in Turkish).
3. Barka, A.A., 1992. The North Anatolian fault zone, Annales Tectonice, special Issue-Supplement to Volume VI, pp. 164–195.
4. Squeezing rocks in tunnels;Barla;Int. Soc. Rock Mech., News J.,1995
5. The Q-System following twenty years of application in NMT support selection;Barton;Felsbau,1994