@article{JRAM_1905__129_149203,
     author = {David Hilbert},
     title = {\"Uber das {Dirichletsche} {Prinzip.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {63--67},
     publisher = {mathdoc},
     volume = {129},
     year = {1905},
     zbl = {36.0442.01},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1905__129_149203/}
}