@article{RM_1967_22_3_a8,
     author = {A. Yu. Levin},
     title = {Convex and quasi-convex systems of equations},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     publisher = {mathdoc},
     volume = {22},
     number = {3},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1967_22_3_a8/}
}