1. Prediction of penetration and utilization for hard rock TBMs;Alber,1996
2. Classifying TBM Contracts;Alber;Tunnels & Tunnelling,1996
3. Design of high speed TBM-drives;Alber,1998
4. Engineering Rock Mass Classifications;Bieniawski,1989
5. Influence ofgeological parameters on TBM advance rates (in German);Büchi,1984