@article{IM2_1968_2_4_a12,
     author = {G. N. Tyurina},
     title = {On the tautness of rationally contractible curves on a surface},
     journal = {Izvestiya. Mathematics},
     pages = {907--934},
     year = {1968},
     volume = {2},
     number = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1968_2_4_a12/}
}