@article{01932959,
title = {Hasse invariant and group cohomology.},
journal = {Documenta Mathematica},
volume = {8},
year = {2003},
pages = {43-50},
zbl = {1044.11030},
language = {en},
url = {http://dml.mathdoc.fr/item/01932959}
}
Edixhoven, Bas; Khare, Chandrashekhar. Hasse invariant and group cohomology.. Documenta Mathematica, Tome 8 (2003) pp. 43-50. http://gdmltest.u-ga.fr/item/01932959/