@article{IM2_1989_33_3_a7,
     author = {V. A. Alexeev},
     title = {Fractional indices of log {Del} {Pezzo} surfaces},
     journal = {Izvestiya. Mathematics },
     pages = {613--629},
     publisher = {mathdoc},
     volume = {33},
     number = {3},
     year = {1989},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1989_33_3_a7/}
}