@article{JRAM_1982__336_152473,
     author = {Mariano Giaquinta and Stefan Hildebrandt},
     title = {A priori estimates for harmonic mappings.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {124--164},
     publisher = {mathdoc},
     volume = {336},
     year = {1982},
     zbl = {0508.58015},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1982__336_152473/}
}