@article{NUMA_1993__65_4_133739,
     author = {W. Spann},
     title = {On the boundary element method for the {Signorini} problem of the {Laplacian.}},
     journal = {Numerische Mathematik},
     pages = {337--356},
     publisher = {mathdoc},
     volume = {65},
     number = {4},
     year = {1993},
     zbl = {0798.65106},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1993__65_4_133739/}
}