@article{IM2_1974_8_4_a1,
     author = {B. Yu. Weisfeiler and I. V. Dolgachev},
     title = {Unipotent group schemes over integral rings},
     journal = {Izvestiya. Mathematics},
     pages = {761--800},
     year = {1974},
     volume = {8},
     number = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1974_8_4_a1/}
}