@article{CMH_1948__21_138934,
     author = {Nora Cattaneo},
     title = {Sopra alcune curve covarianti delle linee piane.},
     journal = {Commentarii mathematici Helvetici},
     pages = {67--72},
     publisher = {mathdoc},
     volume = {21},
     year = {1948},
     zbl = {0030.36301},
     url = {http://geodesic.mathdoc.fr/item/CMH_1948__21_138934/}
}