@article{IM_1985__82_143299,
     author = {E.M. Stein and C.D. Sogge},
     title = {Averages of functions over hypersurfaces in {Rn.}},
     journal = {Inventiones mathematicae},
     pages = {543--556},
     publisher = {mathdoc},
     volume = {82},
     year = {1985},
     zbl = {0626.42009},
     url = {http://geodesic.mathdoc.fr/item/IM_1985__82_143299/}
}