@article{SEDP_1989-1990____A1_0,
     author = {Lerner, N. and Nourrigat, J.},
     title = {Lower bounds for pseudo-differential operators},
     journal = {S\'eminaire \'Equations aux d\'eriv\'ees partielles (Polytechnique) dit aussi "S\'eminaire Goulaouic-Schwartz"},
     note = {talk:1},
     pages = {1--8},
     publisher = {Ecole Polytechnique, Centre de Math\'ematiques},
     year = {1989-1990},
     zbl = {0729.35151},
     language = {en},
     url = {http://www.numdam.org/item/SEDP_1989-1990____A1_0/}
}