@incollection{JEDP_1977____33_0,
     author = {Bolley, Pierre and Camus, Jacques and Pham The Lai},
     title = {Noyau, r\'esolvante et valeurs propres d'une classe d'op\'erateurs elliptiques et d\'eg\'en\'er\'es},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     pages = {33--46},
     publisher = {Ecole polytechnique},
     year = {1977},
     mrnumber = {81b:35078},
     zbl = {0389.35036},
     language = {fr},
     url = {http://archive.numdam.org/item/JEDP_1977____33_0/}
}