@article{10_2307_121025,
     author = {Se\'an Keel},
     title = {Basepoint freeness for nef and big line bundles in positive characteristic},
     journal = {Annals of mathematics},
     year = {1999},
     volume = {149},
     number = {1},
     doi = {10.2307/121025},
     zbl = {0954.14004},
     url = {http://geodesic.mathdoc.fr/articles/10.2307/121025/}
}