TY - SER AU - Clegg,Nigel TI - 3D inversion of ultradeep electromagnetic data: A 3D inversion of ultradeep EM data provides a useful tool for identifying a change in resistivity all around the borehole PY - 2020/// UR - http://digitaledition.epmag.com/publication/?m=61175&i=668457&p=48 ER -