@article{JRAM_1987__382_152980,
     author = {Carlos A. Berenstein and P.C. Yang},
     title = {An inverse {Neumann} problem.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {1--21},
     publisher = {mathdoc},
     volume = {382},
     year = {1987},
     zbl = {0623.35078},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1987__382_152980/}
}