@article{IM2_1994_42_2_a5,
     author = {V. V. Shokurov},
     title = {Semistable 3-fold flips},
     journal = {Izvestiya. Mathematics},
     pages = {371--425},
     year = {1994},
     volume = {42},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1994_42_2_a5/}
}