@article{M2AN_2005__39_2_419_0,
     author = {Zuppa, Carlos},
     title = {Lagrange multipliers for higher order elliptic operators},
     journal = {ESAIM: Mod\'elisation math\'ematique et analyse num\'erique},
     pages = {419--429},
     publisher = {EDP-Sciences},
     volume = {39},
     number = {2},
     year = {2005},
     doi = {10.1051/m2an:2005013},
     mrnumber = {2143954},
     zbl = {1078.65111},
     language = {en},
     url = {http://www.numdam.org/articles/10.1051/m2an:2005013/}
}