@article{ASNSP_1997_4_24_1_63_0,
     author = {Kachi, Yasuyuki},
     title = {Extremal contractions from $4$-dimensional manifolds to $3$-folds},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {63--131},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 24},
     number = {1},
     year = {1997},
     mrnumber = {1475773},
     zbl = {0908.14002},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1997_4_24_1_63_0/}
}