@article{10_1090_S0894_0347_03_00443_0,
     author = {Keel, Markus and Smith, Hart and Sogge, Christopher},
     title = {Almost global existence for quasilinear wave equations in three space dimensions},
     journal = {Journal of the American Mathematical Society},
     pages = {109--153},
     publisher = {mathdoc},
     volume = {17},
     number = {1},
     year = {2004},
     doi = {10.1090/S0894-0347-03-00443-0},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-03-00443-0/}
}