@article{ZNSL_2004_310_a2,
     author = {I. Athanasopoulos and L. A. Caffarelli},
     title = {Optimal regularity of lower dimensional obstacle problems},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {49--66},
     publisher = {mathdoc},
     volume = {310},
     year = {2004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2004_310_a2/}
}