@article{BUMI_1964_3_19_3_a5,
     author = {Barozzi, Giulio Cesare},
     title = {Sul multi-indice degli operatori quasi-ellittici.},
     journal = {Bollettino della Unione matematica italiana},
     pages = {289--299},
     publisher = {mathdoc},
     volume = {Ser. 3, 19},
     number = {3},
     year = {1964},
     zbl = {0141.28601},
     mrnumber = {170106},
     language = {it},
     url = {http://geodesic.mathdoc.fr/item/BUMI_1964_3_19_3_a5/}
}