@article{GDZPPN002109093,
title = {Unstable vector bundles and linear systems on surfaces in characteristic p.},
journal = {Inventiones mathematicae},
volume = {104},
year = {1991},
pages = {243-262},
zbl = {0769.14006},
url = {http://dml.mathdoc.fr/item/GDZPPN002109093}
}
Shepherd-Barron, N.I. Unstable vector bundles and linear systems on surfaces in characteristic p.. Inventiones mathematicae, Tome 104 (1991) pp. 243-262. http://gdmltest.u-ga.fr/item/GDZPPN002109093/