@article{IM_1985__81_143259,
     author = {Tetsuya Ando},
     title = {On extremal rays of the higher dimensional varieties.},
     journal = {Inventiones mathematicae},
     pages = {347--358},
     publisher = {mathdoc},
     volume = {81},
     year = {1985},
     zbl = {0554.14001},
     url = {http://geodesic.mathdoc.fr/item/IM_1985__81_143259/}
}