@article{NUMA_1981__37_132720,
     author = {N. Kikuchi},
     title = {Convergence of a {Penalty-Finite} {Element} {Approximation} for an {Obstacle} {Problem.}},
     journal = {Numerische Mathematik},
     pages = {105--120},
     publisher = {mathdoc},
     volume = {37},
     year = {1981},
     zbl = {0469.65044},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1981__37_132720/}
}