@article{IM_1991__104_1_143887,
     author = {Christopher D. Sogge},
     title = {Propagation of singularities and maximal functions in the plane.},
     journal = {Inventiones mathematicae},
     pages = {349--376},
     publisher = {mathdoc},
     volume = {104},
     number = {1},
     year = {1991},
     zbl = {0754.35004},
     url = {http://geodesic.mathdoc.fr/item/IM_1991__104_1_143887/}
}