@article{ASNSP_1964_3_18_3_255_0,
     author = {Schechter, Martin},
     title = {On the dominance of partial differential operators {II}},
     journal = {Annali della Scuola Normale Superiore di Pisa - Scienze Fisiche e Matematiche},
     pages = {255--282},
     publisher = {Scuola normale superiore},
     volume = {Ser. 3, 18},
     number = {3},
     year = {1964},
     mrnumber = {188614},
     zbl = {0125.05903},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1964_3_18_3_255_0/}
}