@article{STO_1982_1982_1_a7,
     author = {Guccione, Salvatore and Tortora, Roberto},
     title = {Jerarqu{\'\i}a sem\'antica para f\'ormulas modales.},
     journal = {Stochastica},
     pages = {71-77},
     publisher = {mathdoc},
     volume = {6},
     number = {1},
     year = {1982},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/STO_1982_1982_1_a7/}
}