@article{SEDP_1972-1973____A27_0,
     author = {Beals, R. and Fefferman, C.},
     title = {Classes of spatially inhomogeneous pseudodifferential operators},
     journal = {S\'eminaire \'Equations aux d\'eriv\'ees partielles (Polytechnique) dit aussi "S\'eminaire Goulaouic-Schwartz"},
     note = {talk:26},
     pages = {1--6},
     publisher = {Ecole Polytechnique, Centre de Math\'ematiques},
     year = {1972-1973},
     mrnumber = {397480},
     zbl = {0257.35081},
     language = {en},
     url = {http://www.numdam.org/item/SEDP_1972-1973____A27_0/}
}