@article{RM_1960_15_5_a14,
     author = {V. V. Goldberg},
     title = {Surfaces $L$ of four-dimensional space and their maps into three-dimensional space},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1960},
     volume = {15},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1960_15_5_a14/}
}