@article{TM_1991_200_a7,
     author = {V. S. Vinogradov},
     title = {On the reduction of elliptic system of order one on the plane to the complex special form},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {84--87},
     publisher = {mathdoc},
     volume = {200},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1991_200_a7/}
}