@article{NUMA_1986__49_133118,
     author = {John W. Barrett and Charles M. Elliott},
     title = {Finite {Element} {Approximation} of the {Dirichlet} {Problem} {Using} the {Boundary} {Penalty} {Method.}},
     journal = {Numerische Mathematik},
     pages = {343--366},
     publisher = {mathdoc},
     volume = {49},
     year = {1986},
     zbl = {0614.65116},
     url = {http://geodesic.mathdoc.fr/item/NUMA_1986__49_133118/}
}