@article{ZVMMF_1989_29_12_a4,
     author = {S. I. Serdyukova},
     title = {An estimate of the {\textquotedblleft}shade{\textquotedblright} of additional boundary conditions for systems of difference equations with oblique characteristics of constant sign},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {1811--1821},
     publisher = {mathdoc},
     volume = {29},
     number = {12},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1989_29_12_a4/}
}