@article{RM_1968_23_3_a11,
     author = {A. B. Katok and C. Foias},
     title = {Multiplicative operator functions of a~metric automorphism},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1968},
     volume = {23},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1968_23_3_a11/}
}