@article{RM_1977_32_3_a23,
     author = {P. S. Aleksandrov},
     title = {In memory of {Heinz} {Hopf}},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1977},
     volume = {32},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1977_32_3_a23/}
}