@article{SM_2003_194_11_a2,
     author = {V. N. Kokarev},
     title = {On the equation of an~improper convex affine sphere:},
     journal = {Sbornik. Mathematics},
     pages = {1647--1663},
     year = {2003},
     volume = {194},
     number = {11},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2003_194_11_a2/}
}