@article{CMH_1981__56_139854,
     author = {Maurizio Cornalba and Enrico Arbarello},
     title = {Su una congettura di {Petri.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {1--37},
     publisher = {mathdoc},
     volume = {56},
     year = {1981},
     language = {it},
     url = {http://geodesic.mathdoc.fr/item/CMH_1981__56_139854/}
}