@article{RM_1994_49_5_a4,
     author = {B. M. Levitan},
     title = {On the work of {Nikolai} {Nikolaevich} {Bogolyubov} in the theory of almost periodic functions},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {77--88},
     publisher = {mathdoc},
     volume = {49},
     number = {5},
     year = {1994},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1994_49_5_a4/}
}