@article{AM_1999_150_2_a2,
     author = {Michael Christ and Alexander Nagel and Elias M. Stein and Stephen Wainger},
     title = {Singular and maximal {Radon} transforms: {Analysis} and geometry},
     journal = {Annals of mathematics},
     publisher = {mathdoc},
     volume = {150},
     number = {2},
     year = {1999},
     url = {http://geodesic.mathdoc.fr/item/AM_1999_150_2_a2/}
}