@article{IM_1977__43_142506,
     author = {Yves Colin de Verdiere},
     title = {Quasi-modes sur les vari\'et\'es {Riemanniennes.}},
     journal = {Inventiones mathematicae},
     pages = {15--52},
     publisher = {mathdoc},
     volume = {43},
     year = {1977},
     zbl = {0449.53040},
     url = {http://geodesic.mathdoc.fr/item/IM_1977__43_142506/}
}