@article{MAN_1987__278_164298,
     author = {Gerard van der Geer},
     title = {Note on the {Abelian} {Schemes} of {Level} {Three.}},
     journal = {Mathematische Annalen},
     pages = {401--408},
     publisher = {mathdoc},
     volume = {278},
     year = {1987},
     zbl = {0688.14034},
     url = {http://geodesic.mathdoc.fr/item/MAN_1987__278_164298/}
}