@article{SEDP_1970-1971____A18_0,
     author = {Tougeron, J. Cl.},
     title = {Id\'eaux ferm\'es de fonctions $C^\infty $},
     journal = {S\'eminaire \'Equations aux d\'eriv\'ees partielles (Polytechnique) dit aussi "S\'eminaire Goulaouic-Schwartz"},
     note = {talk:18},
     pages = {1--11},
     publisher = {Ecole Polytechnique, Centre de Math\'ematiques},
     year = {1970-1971},
     zbl = {0251.46028},
     language = {fr},
     url = {http://www.numdam.org/item/SEDP_1970-1971____A18_0/}
}