@article{AM_2000_152_1_a3,
     author = {Frans Oort},
     title = {Newton polygons and formal groups: {Conjectures} by {Manin} and {Grothendieck}},
     journal = {Annals of mathematics},
     publisher = {mathdoc},
     volume = {152},
     number = {1},
     year = {2000},
     url = {http://geodesic.mathdoc.fr/item/AM_2000_152_1_a3/}
}