@incollection{MSMF_1973__34__55_0, author = {Bolley, Pierre and Camus, Jacques}, title = {Sur une classe d'op\'erateurs elliptiques et d\'eg\'en\'er\'es \`a plusieurs variables}, booktitle = {Contributions \`a l'analyse fonctionnelle}, author = {Collectif}, series = {M\'emoires de la Soci\'et\'e Math\'ematique de France}, pages = {55--140}, publisher = {Soci\'et\'e math\'ematique de France}, number = {34}, year = {1973}, doi = {10.24033/msmf.112}, zbl = {0268.35037}, mrnumber = {58 #1618}, url = {http://www.numdam.org/articles/10.24033/msmf.112/} }