@article{RM_1963_18_6_a9,
     author = {Yu. L. Shmul'yan},
     title = {Non-expanding operators in a~finite-dimensional space with indefinite metric},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1963},
     volume = {18},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1963_18_6_a9/}
}