@article{TM_2017_297_a17,
     author = {I. V. Vyugin and R. I. Levin},
     title = {On the {Riemann{\textendash}Hilbert} problem for difference and $q$-difference systems},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {326--343},
     year = {2017},
     volume = {297},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_2017_297_a17/}
}