@article {1989,
	title = {A pointwise regularity theory for the two-obstacle problem},
	journal = {Acta Math.  163  (1989),  no. 1-2, 57-107},
	number = {SISSA;47/88/M},
	year = {1989},
	publisher = {SISSA Library},
	url = {http://hdl.handle.net/1963/643},
	author = {Gianni Dal Maso and Umberto Mosco and Maria Agostina Vivaldi}
}
