@article{DAN_1957_116_5_a3,
     author = {S. I. Zukhovitskii and G. I. \`Eskin},
     title = {The approximation of abstract continuous functions by unbounded operator-functions},
     journal = {Doklady Akademii Nauk},
     pages = {731--734},
     publisher = {mathdoc},
     volume = {116},
     number = {5},
     year = {1957},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1957_116_5_a3/}
}