@article{DAN_1988_301_2_a0,
     author = {Ya. S. Baris},
     title = {A method of constructing approximate integral manifolds},
     journal = {Doklady Akademii Nauk},
     pages = {265--267},
     publisher = {mathdoc},
     volume = {301},
     number = {2},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1988_301_2_a0/}
}