@article{DAN_1988_303_1_a1,
     author = {D. Yu. Grigor'ev},
     title = {Complexity of the factorization of a linear ordinary differential},
     journal = {Doklady Akademii Nauk},
     pages = {16--20},
     publisher = {mathdoc},
     volume = {303},
     number = {1},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1988_303_1_a1/}
}