@article{RSMUP_1977__57__217_0,
     author = {Plazzi, Piero},
     title = {Un teorema di $L^2$ continuit\`a per certi operatori pseudodifferenziali},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {217--230},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {57},
     year = {1977},
     mrnumber = {526193},
     zbl = {0398.35091},
     language = {it},
     url = {http://www.numdam.org/item/RSMUP_1977__57__217_0/}
}