@article{IM2_1986_26_3_a5,
     author = {V. V. Shokurov},
     title = {The nonvanishing theorem},
     journal = {Izvestiya. Mathematics},
     pages = {591--604},
     year = {1986},
     volume = {26},
     number = {3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1986_26_3_a5/}
}