@article{PM_2001_2001_1_a4,
     author = {Egorov, Yuri V. and El Aidi, Mohammed},
     title = {Espectro negativo de un operador el{\'\i}ptico con condiciones de contorno de {Robin.}},
     journal = {Publicacions matem\`atiques},
     pages = {125-148},
     publisher = {mathdoc},
     volume = {45},
     number = {1},
     year = {2001},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/item/PM_2001_2001_1_a4/}
}