@article{DAN_1989_304_2_a14,
     author = {R. H. Aminov and B. G. Gabdulkhaev},
     title = {Approximate solution of the {Ambartsumyan} functional equation},
     journal = {Doklady Akademii Nauk},
     pages = {322--325},
     publisher = {mathdoc},
     volume = {304},
     number = {2},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_304_2_a14/}
}