@article{10_1090_S0894_0347_1989_0999662_3,
     author = {Sogge, Christopher D.},
     title = {Oscillatory integrals and unique continuation for second order elliptic differential equations},
     journal = {Journal of the American Mathematical Society},
     pages = {491--515},
     publisher = {mathdoc},
     volume = {02},
     number = {3},
     year = {1989},
     doi = {10.1090/S0894-0347-1989-0999662-3},
     url = {http://geodesic.mathdoc.fr/articles/10.1090/S0894-0347-1989-0999662-3/}
}