@article{AM_1998_148_3_a6,
     author = {Diego Cordoba},
     title = {Nonexistence of simple hyperbolic blow-up for the quasi-geostrophic equation},
     journal = {Annals of mathematics},
     publisher = {mathdoc},
     volume = {148},
     number = {3},
     year = {1998},
     url = {http://geodesic.mathdoc.fr/item/AM_1998_148_3_a6/}
}