@article{ZNSL_1990_180_a12,
     author = {A. P. Oskolkov and R. Shadiev},
     title = {To the theory of global solvability},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {121--141},
     year = {1990},
     volume = {180},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1990_180_a12/}
}