Optimal regularity of lower dimensional obstacle problems. Athanasopoulos, I.; Caffarelli, L.A. — 2004 Journal of Mathematical Sciences (New York)
The Obstacle Problem Revisited. L.A. Caffarelli — 1998 The journal of Fourier analysis and applications [[Elektronische Ressource]]
Existence and regularity for a minimum problem with free boundary. H.W. Alt; L.A. Caffarelli — 1981 Journal für die reine und angewandte Mathematik