Einstein, H.H. (1996). Tunnelling in difficult ground — Swelling behaviour and identification of swelling rocks. Rock Mechanics and Rock Engineering, 29 (3), 113-124. doi:10.1007/BF01032649
Einstein, H.H. (1996). Tunnelling in difficult ground — Swelling behaviour and identification of swelling rocks. Rock Mechanics and Rock Engineering, 29 (3), 113-124. doi:10.1007/BF01032649