RT Journal Article SR Electronic(1) A1 Ashida, Y.YR 1997 T1 Looking Forward of Tunnel Face by Use of Equi-traveltime Planes JF , VO OP SP cp-422-00001 DO https://doi.org/10.3997/2352-8265.20140013 PB European Association of Geoscientists & Engineers, SN 2214-4609, AB , UL https://www.earthdoc.org/content/papers/10.3997/2352-8265.20140013