@article{AA_2020_32_4_a1,
     author = {S. Eberle and G. S. Weiss},
     title = {Characterizing compact coincidence sets in the obstacle problem~--- a short proof},
     journal = {Algebra i analiz},
     pages = {137--145},
     publisher = {mathdoc},
     volume = {32},
     number = {4},
     year = {2020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AA_2020_32_4_a1/}
}