@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}, publisher = {mathdoc}, volume = {8}, number = {4}, year = {1974}, language = {en}, url = {http://geodesic.mathdoc.fr/item/IM2_1974_8_4_a1/} }