@article{ASNSP_2003_5_2_3_461_0,
     author = {Manfredini, Sandro},
     title = {A combinatorial approach to singularities of normal surfaces},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {461--491},
     publisher = {Scuola normale superiore},
     volume = {Ser. 5, 2},
     number = {3},
     year = {2003},
     mrnumber = {2020857},
     zbl = {1170.32313},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_2003_5_2_3_461_0/}
}