@article{MM2_1994__83_3-4_155962,
     author = {Frank Duzaar and Joseph F. Grotowski},
     title = {Energy minimizing harmonic maps with an obstacle at the free boundary.},
     journal = {Manuscripta mathematica},
     pages = {291--314},
     publisher = {mathdoc},
     volume = {83},
     number = {3-4},
     year = {1994},
     zbl = {0805.58019},
     url = {http://geodesic.mathdoc.fr/item/MM2_1994__83_3-4_155962/}
}