RT Journal Article SR Electronic(1) A1 Weitzel, H.YR 1997 T1 Planning and constructing gas mains using GPR JF , VO OP SP cp-95-00074 DO https://doi.org/10.3997/2214-4609.201407335 PB European Association of Geoscientists & Engineers, SN 2214-4609, AB , UL https://www.earthdoc.org/content/papers/10.3997/2214-4609.201407335