Einstein, H.H. (2000). Tunnels in Opalinus Clayshale — A review of case histories and new developments. Tunnelling and Underground Space Technology, 15 (1), 13-29. doi:10.1016/S0886-7798(00)00025-0
Einstein, H.H. (2000). Tunnels in Opalinus Clayshale — A review of case histories and new developments. Tunnelling and Underground Space Technology, 15 (1), 13-29. doi:10.1016/S0886-7798(00)00025-0